identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
038587FE5142FFE26AE5FF66DF5EFDC3.text	038587FE5142FFE26AE5FF66DF5EFDC3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bacillariophyta	<div><p>Division Bacillariophyta</p> <p>Class Mediophyceae (Jousé &amp; Proshkina-Lavrenko) Medlin &amp; Kaczmarska 2004</p> <p>Order Chaetocerotales Round &amp; Crawford in Round et al. 1990</p> <p>Family Chaetocerotaceae Ralfs in Pritchard 1861</p> <p>Genus Chaetoceros Ehrenberg 1845</p> <p>Subgenus Chaetoceros Hendey 1964</p></div> 	https://treatment.plazi.org/id/038587FE5142FFE26AE5FF66DF5EFDC3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5142FFE26AE5FD90DCBAFB7F.text	038587FE5142FFE26AE5FD90DCBAFB7F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros coarctatus Lauder 1864	<div><p>Chaetoceros coarctatus Lauder (1864a: 79) (Figs 2, 3)</p> <p>References:— Hustedt (1930), Cupp (1943), Hernández-Becerril (1991a), Nagasawa and Warren (1996), Lee et al. (2014b).</p> <p>Synonyms: — Chaetoceros borealis var. rudis Cleve, Chaetoceros rudis Cleve, Chaetoceros validum Grunow in Cleve &amp; Möller.</p> <p>Morphometry: —apical axis (a.a.): 26–36 μm; pervalvar axis (p.a.): 42–63 μm.</p> <p>LM: —The cells form heteropolar, straight, robust and long chains. Heavily silicified cells are rectangular in girdle view with the diagonally cut valve corners (Fig. 2). Numerous small chloroplasts are present in the cell body and the setae (Fig. 3). The advalvar mantle edge is constricted, mantle is high and equidimensional or smaller than the girdle. Valve surface is flat, setae arise within the valve margin with a very short, and practically non-existent basal part therefore the apertures are extremely narrow and often the valve faces of sibling cells touch each other (Fig 2). The sibling setae cross each other near the chain edge and after crossing point diverge at an angle of about 30–45° from the apical plane. All setae are thick, coarse and curved towards the posterior end of the chain (Fig. 3). No morphologically distinct type of terminal or intercalary setae was observed (Fig. 3).</p> <p>Distinctive features: —Robust chains, large cells with constricted valve edge, very narrow apertures. All setae curved towards one side of the chain. Chains commonly found with epizoic ciliate Vorticella sp. attached to the cells, sometimes in large numbers.</p> </div>	https://treatment.plazi.org/id/038587FE5142FFE26AE5FD90DCBAFB7F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5142FFE26AE5FB74DC07F943.text	038587FE5142FFE26AE5FB74DC07F943.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros dadayi Pavillard 1913	<div><p>Chaetoceros dadayi Pavillard (1913: 131) (Fig. 4)</p> <p>References:— Hustedt (1930), Cupp (1943), Hernández-Becerril (1992).</p> <p>Morphometry: —a.a.: 7–17 μm; p.a.: 7–26 μm.</p> <p>LM: —Heteropolar and short chains, composed of only three cells (Fig. 4), are typically attached to the lorica of the ciliate tintinnid Eutintinnus sp. In girdle view cells are rectangular with round valve corners, valve mantle is not visibly constricted. Numerous chloroplasts are present in the cell body and the setae (Fig. 4). The apertures are either very narrow or absent, and the sibling valve faces are closely pressed on each other. After the crossing point, the setae strongly curve becoming almost parallel with the chain axis, but they differ in their orientation and morphology. Some setae are shorter and oriented towards the posterior end of the chain to embrace the lorica of the tintinnid, whereas two intercalary setae are directed to the anterior chain end (Fig. 4).</p> <p>Distinctive features:—Two setae of the neighbouring cells on the same side directed towards the anterior side of the chain while all other setae are oriented towards posterior side. Lorica of the symbiotic ciliate Eutintinnus sp. attached to the chain.</p> </div>	https://treatment.plazi.org/id/038587FE5142FFE26AE5FB74DC07F943	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5142FFEC6AE5F910D9C6FDD1.text	038587FE5142FFEC6AE5F910D9C6FDD1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros danicus Cleve 1889	<div><p>Chaetoceros danicus Cleve (1889: 55) (Figs 5–12)</p> <p>References:— Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Jensen &amp; Moestrup (1998), Sunesen et al. (2008), Kooistra et al. (2010), Lee et al. (2014b).</p> <p>Morphometry: —a.a.: 12–40 μm; p.a.: 13–23 μm.</p> <p>LM: —Cells are usually solitary but occasionally found in short chains composed of two to three cells. Cells contain numerous small chloroplasts located in the central body and in the setae (Figs 5, 6). The valve face is flat or slightly concave; the mantle is moderately high and the girdle is small. Long and thick setae originate from the valve corners and extend perpendicular to pervalvar axis. They are usually straight, but can also be slightly curved in the apical plane. In the same cell, the two valves are generally rotated to each other at ca. 45° and the setae form a typical cross when observed in valve view (Fig. 5). When two cells are found attached to each other, the setae are fused at the valve corners for a short distance without a basal part but the narrow apertures can still be observed due to the slight concave surface of the valves (Fig. 6).</p> <p>EM: —The valve is ornamented by a small round central annulus with numerous branching costae extending towards the valve edge, and by numerous poroids irregularly scattered over the valve surface, excluding the central part and mantle (Fig. 7). The mantle is constricted near the edge (Fig. 8) and often ornamented by irregular siliceous thickenings (Fig. 9). Every valve possesses a centrally located rimoportula in the form of a simple oval or commashaped hole on the internal side of the valve (Figs 7–9). Setae in cross-section are round at the bases and later become four to six-sided, with a row of arrowhead-shaped spines on each ridge (1–2 spines in 10 μm) (Fig. 10). The setae sides are ornamented by poroids arranged in a grid pattern, 3–5 longitudinal rows of poroids on each setae side and one transverse row between not particularly thick transverse costae (Fig. 11). Girdle bands are ornamented by alternating costae and striae. The band striae are perforated by irregularly scattered small poroids (Fig. 12).</p> <p>Distinctive features: —Usually single cells, straight and thick setae perpendicular to the pervalvar axis, forming a cross in valve view. Setae mainly tetragonal with arrowhead-shaped spines on the ridges and sides pattern consisting of poroids arranged in a grid, 3–5 longitudinal poroid rows, one transverse row between costae.</p></div> 	https://treatment.plazi.org/id/038587FE5142FFEC6AE5F910D9C6FDD1	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514CFFEC6AE5FDA8DE0DFB42.text	038587FE514CFFEC6AE5FDA8DE0DFB42.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros densus (Cleve) Cleve 1901	<div><p>Chaetoceros densus (Cleve) Cleve (1901: 15, 16, 24, 28) (Figs 13–15)</p> <p>References:— Hustedt (1930), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Jensen &amp; Moestrup (1998), Lee et al. (2014b).</p> <p>Synonyms: — Chaetoceros borealis var. densa Cleve, Chaetoceros borealis var. brigthwellii Cleve, Chaetoceros brightwellii (Cleve) Mills.</p> <p>Morphometry: —a.a.: 17–38 μm; p.a.: 13–63 μm</p> <p>LM: —Cells are united into robust, straight and long chains. Cells are rectangular in girdle view with diagonally cut valve corners (Fig. 13). Cells and setae contain numerous small chloroplasts. The valve face is flat or slightly concave; the mantle is high and shows a visible constriction at its edge (Fig. 13). A simple hole-shaped rimoportula is present in the centre of each valve (Fig. 14). The long, thick and straight setae originate inside the valve margin. Apertures are narrow and slit- or hexagonally shaped (Fig. 13). In valve view, the intercalary setae diverge from the apical plane at equal angles (ca. 30–45°) (Fig. 14). Terminal setae are almost parallel to the chain axis.</p> <p>EM: —The setae are four-sided (not shown) with the rows of sharp stipule-shaped spines on the ridges. Each side is perforated by small poroids arranged in a grid pattern, comprising 12–15 longitudinal rows and a single row of poroids between transverse costae (Fig. 15).</p> <p>Distinctive features: —Very narrow apertures. Four-sided setae with each side ornamented with small poroids arranged in a grid pattern, with 12–15 longitudinal rows of poroids.</p></div> 	https://treatment.plazi.org/id/038587FE514CFFEC6AE5FDA8DE0DFB42	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514CFFEC6AE5FB1FD965F83D.text	038587FE514CFFEC6AE5FB1FD965F83D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros eibenii Grunow	<div><p>Chaetoceros eibenii Grunow in Van Heurck (1882: pl. LXXXII) (Figs 16–23)</p> <p>References:— Hustedt (1930), Cupp (1943), Von Stosch et al. (1973), Koch &amp; Rivera (1984), Rines &amp; Hargraves (1988), Jensen &amp; Moestrup (1998), Lee et al. (2014b).</p> <p>Synonym: — Chaetoceros paradoxus var. eibenii Grunow.</p> <p>Morphometry: —a.a.: 13–42 μm; p.a.: 11–38 μm.</p> <p>LM: —Cells united into robust, straight and long chains (Fig. 16). In girdle view cells are rectangular with sharp valve corners (Fig. 17). Cells and setae contain numerous chloroplasts. The valve surface is slightly concave with a spine-like central process visible on every valve (Fig. 17). The valve mantle is low. Setae originate inside the valve margin and have a relatively short basal part (Fig. 17).</p> <p>EM: —The valves are very heavily silicified and perforated with poroids irregularly scattered over the valve face, setae bases, and mantle. In valve view, one seta is oriented parallel to the apical plane and the other one diverges from it at approximately 90° angle (Fig. 18). However, the divergence angle can be quite variable. The marginal ridge is often ornamented with a strongly silicified low hyaline rim with an uneven edge (Fig. 18). A central rimoportula is present in each valve. It appears as a simple hole from the inside, and brings a flattened or round tube with a tapering tip on the outside of the valve (Figs 18–19). The setae are six-sided (Fig. 22) with a row of very strong, shark fin-shaped spines on each ridge (Fig. 23). The setae sides are ornamented by relatively thick and distinct transverse costae interspaced by less silicified areas, which are perforated by numerous very small poroids, sometimes arranged in rows close to costae but otherwise irregularly scattered over the hyaline area (Figs 20–21). One larger round pore is present near the ridge and close to the costa on either sides of the side-wall, at an interval of 4–8 costae (Fig. 21).</p> <p>Distinctive features: —Hexagonal apertures, a spine-like rimoportula process visible in every valve. Six-sided setae, ornamented with thick costae interspaced by numerous very small poroids.</p></div> 	https://treatment.plazi.org/id/038587FE514CFFEC6AE5FB1FD965F83D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514EFFEE6AE5FF55DE3EFCF1.text	038587FE514EFFEE6AE5FF55DE3EFCF1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros peruvianus Brightwell 1856	<div><p>Chaetoceros peruvianus Brightwell (1856: 107) (Figs 24–26)</p> <p>References:— Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Shevchenko et al. (2006), Sunesen et al. (2008), Kooistra et al. (2010).</p> <p>Synonyms: — Chaetoceros convexicornis Mangin, Chaetoceros peruvianus var. currens Peragallo, Chaetoceros peruvioatlanticus Karsten, Chaetoceros chilensis Krasske.</p> <p>Morphometry: —a.a.: 15–39 μm; p.a.: 16–33 μm</p> <p>LM: —Cells are solitary, containing numerous small plastids located in the cell body and in the setae (Figs 24–26). The frustules are heterovalvate with a convex anterior valve and a concave posterior valve. The mantle of both valves is usually high, with a distinct constriction near the mantle edge, and the girdle is small. All setae lie in the apical plane and are oriented towards the same (posterior) end of the cell (Fig. 24). The setae of the anterior valve emerge very close to the valve centre and are drawn up in the pervalvar direction touching each other with a groove between them, and fuse in the valve centre (Fig. 25). The setae then sharply bend back in a curve toward the posterior end of the cell. The posterior setae originate close to the valve margins and then curve from the cell in the same direction as the anterior ones becoming almost parallel to the pervalvar axis. Setae are thick, coarse, long and ornamented with spines visible in LM (Fig. 26).</p> <p>Distinctive features: —Solitary, heterovalvar cells, all setae curved towards the posterior cell end. Basal parts of anterior setae touching each other with a groove between them.</p></div> 	https://treatment.plazi.org/id/038587FE514EFFEE6AE5FF55DE3EFCF1	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514EFFEE6AE5FC81DEA8F94D.text	038587FE514EFFEE6AE5FC81DEA8F94D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros pseudodichaeta Ikari 1926	<div><p>Chaetoceros pseudodichaeta Ikari (1926: 517) (Figs 27–32)</p> <p>References:— Ikari (1926), Hernández-Becerril (2000), Lee et al. (2014b).</p> <p>Morphometry:—a.a.: 4.1–13.2 μm; p.a.: 8.6–28.4 μm.</p> <p>LM: — Cells form short, straight and robust chains, with setae oriented in a three-dimensional space. (Fig. 27). Cells in girdle view appear rectangular with round corners, usually with the pervalvar axis longer than the apical axis. Numerous spherical chloroplasts are present in the cell body as well as inside the long and thick setae. Valves are slightly concave or flat, mantle is high with no distinct constriction near the edge, the girdle is often broader than the mantle. The setae originate inside the valve margin with a prominent basal part extending parallel with the pervalvar axis. The sibling setae fuse at a single point, often crossing each other at the chain margin, and form a wide and rectangular aperture (Fig. 27). Terminal setae originate within the valve margin and they first extend parallel to the pervalvar axis, then slightly bend outward but soon recurve back and become again almost parallel to the chain axis (Fig. 27). A central rimoportula with a long external tubular process is present only on terminal valves (Fig. 28).</p> <p>EM: —The valves are heavily silicified (Figs 29, 30), the valve face is ornamented with thick dichotomously branching costae radiating from a round central annulus (Fig. 31). The sibling setae fuse at a single point and after the junction diverge almost equally at an angle of ca. 30–45° from the apical plane (Fig. 29). Several short siliceous capilli are irregularly distributed across the surface (Fig. 31). The marginal ridge, between valve face and mantle, is adorned with a strongly silicified low hyaline rim which often extends, in the pervalvar direction, into one or several projections of variable shape and length (Fig. 30). The mantle is high and without constriction near the edge. The four-sided setae are ornamented with curved saw blade-shaped spines, which sometimes extend into capilli (Figs 29, 32). Setae sides are ornamented with transverse thickened costae interspaced by two rows of poroids. Sometimes, one round and slightly larger pore is found, situated at either end of the areola row near the seta ridge.</p> <p>Distinctive features: —Orientation of setae in a three-dimensional space. Setae ornamented with long curved saw blade- shaped spines. Long tubular process present only on terminal valves.</p></div> 	https://treatment.plazi.org/id/038587FE514EFFEE6AE5FC81DEA8F94D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514EFFE96AE5F905DF61FCAD.text	038587FE514EFFE96AE5F905DF61FCAD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros rostratus Ralfs	<div><p>Chaetoceros rostratus Ralfs in Lauder (1864a: 79) (Figs 33–41)</p> <p>References:— Hustedt (1930), Giuffrè &amp; Ragusa (1988), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Sunesen et al. (2008), Lee et al. (2014b).</p> <p>Synonym: — Chaetoceros glandazi Mangin.</p> <p>Morphometry: —a.a.: 10–22 μm; p.a.: 16–48 μm.</p> <p>LM: —The chains are robust, straight and short (usually 2–5 cells) (Fig. 33). Cells in girdle view rectangular with more or less rounded corners (Fig. 34). Cells and setae contain numerous plastids (Fig. 35). Valve face slightly to strongly convex; the mantle is high with a visible constriction near the edge, girdle small and equidimensional with the mantle (Fig. 34). Cells are held in a chain by the fusion of a central linkage process (linking spine) and not by the joining of setae. Very long, straight and thick setae originate close to the valve margin and diverge perpendicular to the chain axis (Fig. 33). In the intercalary cells the sibling valves are twisted about 60° between them so the setae arise without touching the setae emerging from the neighbouring valve (Figs 34–35). In valve view, the sibling setae diverge at an angle of ca. 30–45° from the apical plane.</p> <p>EM: —The conically shaped linking spines are of variable length, and can become very short and wide in culture but in field material they are usually long and narrow (Fig. 36). Their surface is completely smooth and may be perforated with a few poroids at the base. The terminal valve lacks the linking spine. A rimoportula is present in each valve and it is positioned slightly eccentric to one side of the spine (Figs 36, 37). The rimoportula appears as a simple slit on the internal side of the valve (Fig. 37) and brings a small protuberance on the external side (Figs 36, 39). Valves are perforated by round poroids irregularly scattered across the valve face, mantle and setae bases (Fig. 39). The valve face is ornamented with a pattern of dense branching costae which radiate from the eccentrically positioned annulus (Fig. 39). The setae are four-sided in cross section with rows of arrowhead-shaped spines along each edge (Figs 38, 41). The ornamentation on the setae wall consists of five transverse rows of poroids arranged in a cross pattern between transverse thickened costae. After each 4–9 costae there is often one larger round pore located near the side edge and close to the costae (Fig. 40).</p> <p>Distinctive features: —Sibling cells connected with central linking spine of variable length. Four-sided setae having a wall ornamented with thick transverse costae interspaced with five poroid rows.</p> <p>Subgenus Hyalochaete Gran 1897</p></div> 	https://treatment.plazi.org/id/038587FE514EFFE96AE5F905DF61FCAD	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5149FFE96AE5FCA5DDA6F7C1.text	038587FE5149FFE96AE5FCA5DDA6F7C1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros affinis Lauder 1864	<div><p>Chaetoceros affinis Lauder (1864a: 78) (Figs 42–53).</p> <p>References:— Hustedt (1930), Cupp (1943), Evensen &amp; Hasle (1975), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Jensen &amp; Moestrup (1998), Berard-Therriault et al. (1999), Shevchenko et al. (2006), Sunesen et al. (2008), Kooistra et al. (2010), Ishii et al. (2011), Lee et al. (2014a).</p> <p>Synonyms: — Chaetoceros javanicus Cleve, Chaetoceros ralfsii Cleve, Chaetoceros schüttii Cleve, Chaetoceros angulatus Schütt, Chaetoceros distichus Schütt, Chaetoceros procerus Schütt, Chaetoceros paradoxus var. schüttii Schütt, Chaetoceros clevei Peragallo, Chaetoceros raflsii Karsten, Chaetoceros schüttii var. genuina Meunier, Chaetoceros najadianus Schussnig, Chaetoceros adriaticus Schussnig.</p> <p>Morphometry: —a.a.: 9–42 μm; p.a.: 8–16 μm.</p> <p>LM: —The cells are united in straight chains (Fig. 42). Each cell contains a single large chloroplast. The valve surface is concave and the valve corners are sharp and slightly drawn up. Intercalary setae are thin, originating from the valve apices and immediately cross each other at the chain margin. Apertures are rather narrow but usually distinct in LM, slit-shaped to elliptical. Setae are very straight and positioned in the apical plane. Terminal setae can be similar or can differ very strongly from the intercalary ones, in both orientation and morphology. When different, they are much thicker and taper towards the end, strongly diverging in a broad V- (not shown) or U-shaped (Fig. 42) curve towards the end of the chain, lying in the apical plane. The resting spores have unevenly vaulted valves with a broad distinct mantle. Primary valve is dome-shaped, ornamented with numerous long spines whereas the secondary valve has a central inflated part and it is ornamented with few longer spines (Fig. 50).</p> <p>EM: —Valve mantle is high and often with a visible constriction near the margin (Fig. 43). The aperture is very often completely occluded by a thin silica wall with no distinct pattern, except for the single row of pores on its edge where it fuses with the marginal ridge (Fig. 43). The smooth silica membrane is very fragile and appears ruptured in some of the observed specimens. The valves have a pattern of dichotomously branching costae radiating from a round central annulus and are perforated with numerous irregularly shaped very small poroids (Fig. 44). The marginal ridge is ornamented with a hyaline rim (Fig. 45). Terminal valves possess a central slit-shaped rimoportula that forms an external process shaped as a wide, short, flattened tube (Fig. 46). Terminal valves are generally ornamented with few short capilli covering the valve face in the central part (Fig. 45). Intercalary setae are circular in cross-section (Fig. 47) and ornamented with small poroids and shark fin-shaped spines arranged in a spiral pattern (Fig. 48). Terminal setae are heavily silicified with stronger spines and few larger elongated pores irregularly distributed along the seta length (Fig. 49). The surface of the resting spores is covered with knobs and spines, which can be simple or have dichotomously branching tips (Figs 51, 52). The mantle of the secondary valve possesses one single row of puncta (Figs 51, 53).</p> <p>Distinctive features: —Narrow apertures, completely occluded by a silica membrane observable in EM.Intercalary setae straight, all setae lying in the apical plane. Terminal setae often thicker. Resting spores with numerous long spines.</p></div> 	https://treatment.plazi.org/id/038587FE5149FFE96AE5FCA5DDA6F7C1	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE514BFFF46AE5FF56DD9DFD39.text	038587FE514BFFF46AE5FF56DD9DFD39.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros anastomosans Grunow	<div><p>Chaetoceros anastomosans Grunow in Van Heurck (1882: pl. 82) (Figs 54–62)</p> <p>References:— Hustedt (1930), Cupp (1943), Hernández-Becerril &amp; Flores Granados (1998), Hernández-Becerril &amp; Aké-Castillo (2001), Shevchenko et al. (2006), Lee et al. (2014b).</p> <p>Synonyms: — Chaetoceros anastomosans var. speciosa Schutt, Chaetoceros anastomosans var. genuina Cleve-Euler, Chaetoceros externus Gran, Chaetoceros anastomosans var. externa (Gran) Hustedt.</p> <p>Morphometry: —a.a.: 8–10 μm; p.a.: 5–14 μm.</p> <p>LM: —The cells are united in usually long, straight to slightly curved chains (Fig. 54). In girdle view cells are nearly squared to rectangular with the rounded valve corners (Fig. 55). There are two chloroplasts per cell, positioned within each valve (Fig. 55). The valve face is flat or slightly convex. Valve mantle is low with a very slight constriction near the margin. The thin and delicate setae originate from the valve corners. Intercalary setae generally bend at right angles or extend perpendicular to the chain axis. In the valve view they diverge almost equally at an angle of ca. 30–45° from the apical plane (Fig. 56). Cells are connected by a siliceous cross-bridge of variable length which joins sibling setae at a short distance from the valves (Fig. 55). The sibling setae do not cross and form wide apertures that have an unusual, octagonal shape, elongated in the apical direction (Fig. 55). The terminal setae diverge obliquely towards the chain axis becoming almost parallel with it, forming U-shape (Fig. 54).</p> <p>EM: —The valves have a relatively large central annulus from which dichotomously branching costae radiate toward the margins (Figs 57, 58). The marginal ridge is ornamented with a hyaline rim often extended in short projections in the pervalvar direction (Figs 56, 57). A slit-shaped rimoportula is present only in terminal valves (Fig. 59). Girdle bands are narrow and ornamented with alternating transverse hyaline striae and costae (Fig. 60). The setae are circular in cross-section, ornamented with minute arrowhead-shaped spines and poroids running spirally throughout. Additional elongated poroids are randomly distributed along the setae length (Fig. 61). The cross-bridge appears as a hyaline tube with a swelling in the central part, fused on the setae surface (Figs 56, 61).</p> <p>Distinctive features: —Cells connected in chains by a cross-bridge which joins sibling setae. Absence of setae crossing.</p></div> 	https://treatment.plazi.org/id/038587FE514BFFF46AE5FF56DD9DFD39	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5154FFF46AE5FCC9D9BAF94D.text	038587FE5154FFF46AE5FCC9D9BAF94D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros brevis Schutt 1895	<div><p>Chaetoceros brevis Schutt (1895: 38) (Figs 63–71)</p> <p>References:— Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988) (as Chaetoceros cf. brevis), Hernández-Becerril (1996), Jensen &amp; Moestrup (1998), Bérard-Therriault et al. (1999), Sunesen et al. (2008).</p> <p>Synonyms: — Chaetoceros hiemalis (Cleve) Cleve, Chaetoceros didymus var. hiemalis Cleve, Chaetoceros pseudobrevis Pavillard.</p> <p>Morphometry: —a.a.: 14–37 μm; p.a.: 9–40 μm.</p> <p>LM: —Cells are united in straight chains (Fig. 63). Cells are cylindrical, rectangular in girdle view with sharp and drawn up corners. Each cell has a single chloroplast often located close to one valve (Fig. 64). The mantle is low with a slight constriction near the margin. Setae originate from the drawn up valve corners and cross immediately at the chain margin. Apertures are wide and peanut-shaped due to the presence of a central inflation on the sibling valves (Fig. 64). Intercalary setae extend almost parallel to the valvar plane and symmetrically diverge from the apical plane. Setae of the intercalary cells positioned in the centre of the chain are mostly oriented perpendicular to the chain axis while those near the chain end have setae curved towards that end. The terminal setae form a U-shape. Setae very often contain some unknown plastid-like material, which did not fluoresce under UV light, indicating they do not contain chlorophyll (Fig. 65).</p> <p>EM: —Resting spores have the primary valve ornamented with numerous thin capilli and a distinct mantle region (Fig. 66). The valve has a central annulus from which radiate widely spaced parallel and scarcely dichotomously branched costae (Fig. 67). A central slit-shaped rimoportula bearing an external wide flattened tube is present only in terminal valves (Figs 67, 68). The area between costae is hyaline; however, in the centre of the intercalary valve face there is a slightly more silicified area, which in TEM observations appears as a large and irregularly shaped darker patch (Fig. 69). The marginal ridge usually possesses a very low hyaline rim from which, sometimes in terminal valves, extend irregular silica projections (Fig. 68). The girdle bands are ornamented with alternating transverse parallel costae and hyaline striae that are perforated by small and irregularly distributed poroids (Fig. 70). The setae are circular in cross-section, adorned with densely distributed sharkfin-shaped spines and small poroids (Fig. 71).</p> <p>Distinctive features: —Valve face with a central inflation. Thin setae cointaining plastid-like material. Dark patch in the central area of the valve surface. Primary valve of resting spore with numerous thin capilli.</p></div> 	https://treatment.plazi.org/id/038587FE5154FFF46AE5FCC9D9BAF94D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5154FFF76AE5F905D8F4FE35.text	038587FE5154FFF76AE5F905D8F4FE35.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros circinalis (Meunier) Jensen & Moestrup 1998	<div><p>Chaetoceros circinalis (Meunier) Jensen &amp; Moestrup (1998: 28) (Figs 72–78)</p> <p>References:— Hustedt (1930) (as Chaetoceros affinis var. circinalis), Cupp (1943) (as Chaetoceros affinis var. circinalis), Jensen &amp; Moestrup (1998).</p> <p>Synonyms:— Chaetoceros schüttii var. circinalis Meunier, Chaetoceros affinis var. circinalis (Meunier) Hustedt.</p> <p>Morphometry: —a.a.: 5–16 μm; p.a.: 10–28 μm.</p> <p>LM: —The cells are usually united in short, straight chains but single cells were commonly observed in both culture and field material (Fig. 72). Each cell contains a single chloroplast. The valve face is flat or slightly concave with sharp valve corners slightly drawn up to touch the sibling valve. Valve mantle is high, girdle low or equidimensional with the mantle. Intercalary setae originate from the valve corners and immediately fuse at the chain margin. Apertures are very narrow and slit-shaped. Intercalary setae characteristically curve backwards around the cell away from the apical axis (Fig. 73). In girdle view, setae curve strongly towards either side of the chain (Fig. 72). Terminal setae diverge in a broad U-shaped curve often lying in the apical plane.</p> <p>EM: —The valve face and the advalvar part of the mantle are densely perforated by numerous irregularly shaped and relatively large poroids (Figs 74–76). The annulus and costae pattern are hardly observable in TEM due to the height of the mantle (Fig. 76). The marginal ridge is ornamented with a distinct hyaline rim, close to the valve apices, that extends into projections that fuse with corresponding structures of the sibling valve (Fig. 74). Terminal valves are often ornamented with short capilli (Fig. 75) and possess a central rimoportula bearing an external, more or less flattened, wide tube (Figs 75, 76). Intercalary setae appear completely smooth in the proximal portion and further on ornamented with longitudinal straight rows of small poroids and few larger elongated pores (Fig. 77). On the central part of the setae and towards the distal part only small poroids are present together with spirally arranged sharkfin-shaped spines (Fig. 78).</p> <p>Distinctive features: —Intercalary setae characteristically curved backwards around the cell away from the apical axis. Valve face and advalvar part of the mantle densely perforated by many irregular and relatively large poroids.</p></div> 	https://treatment.plazi.org/id/038587FE5154FFF76AE5F905D8F4FE35	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5157FFF76AE5FDCDD9A3FB45.text	038587FE5157FFF76AE5FDCDD9A3FB45.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros constrictus Gran 1897	<div><p>Chaetoceros constrictus Gran (1897: 17) (Figs 79–82)</p> <p>References:— Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Jensen &amp; Moestrup (1998), Hernández-Becerril &amp; Flores Granados (1998), Berard-Therriault et al. (1999), Shevchenko et al. (2006), Lee et al. (2014a).</p> <p>Morphometry: —a.a.: 5–18 μm; p.a.: 7–17 μm.</p> <p>LM:—Cells are united in very straight and usually short chains (Fig. 79). The valve surface is concave and the valve corners are sharp and drawn up, touching between sibling valves (Fig. 81). The aperture is quite large and distinctively elliptically shaped (Figs 79, 81). Valve mantle is high with a distinct constriction near the margin (Fig. 81). Intercalary setae are long and rigid; originate from the valve apices and immediately cross each other at the chain margin without the basal part. In girdle view they are usually proximally perpendicular towards the chain axis and distally curved (Fig. 79). Terminal setae are usually characteristically oriented, long and straight, extending parallel to the chain axis and sometimes crossing each other distally (Fig. 79).</p> <p>EM: —The valve face is ornamented with numerous small spines which are more pronounced in terminal valves (Fig. 82). The marginal ridge has a distinct hyaline rim (Fig. 82). A rimoportula, bearing an external short, flattened and wide tube, is present only in terminal valves (Fig. 82). Setae are quadrangular in cross-section, perforated with longitudinal rows of small slit-shaped poroids and small spines (Fig. 80).</p> <p>Distinctive features: —Valve mantle markedly constricted near the advalvar margin, observable in LM as a marked constriction near the girdle. Intercalary setae long, straight and rigid, terminal setae extending parallel to the chain axis sometimes distally crossing each other. Valve face ornamented with many small spines.</p></div> 	https://treatment.plazi.org/id/038587FE5157FFF76AE5FDCDD9A3FB45	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5157FFF16AE5FB1DDDAEFEC9.text	038587FE5157FFF16AE5FB1DDDAEFEC9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chateoceros contortus Schutt 1895	<div><p>Chateoceros contortus Schütt (1895: 44) (Figs 83–94)</p> <p>References:— Rines and Hargraves (1988) (as C. compressus), Jensen &amp; Moestrup (1998), Bérard-Therriault et al. (1999), Rines (1999), Sunesen et al. (2008), Kooistra et al. (2010), Shevchenko &amp; Orlova (2010), Lee &amp; Lee (2011), Lee et al. (2014a), Chamnansip et al. (2015).</p> <p>Morphometry: —a.a.: 6–23 μm; p.a.: 7–24 μm.</p> <p>LM: —Cells are united in long and straight chains, often twisted about the chain axis (Fig. 83). Cells are cylindrical, in girdle view rectangular with markedly rounded corners, in valve view nearly circular. Cells contain 5–12 small discoid-like chloroplasts (Fig. 84). The valve face is slightly convex with a central inflation. The mantle is more or less high with the girdle equidimensional or wider than the mantle. The setae originate within the valve margin and cross each other at the chain margin after a basal part of medium length (Fig. 84). The apertures are relatively wide, and have a hexagonal shape (Figs 84, 86). There are two types of intercalary setae: common and special. Common setae are thin, generally oriented almost perpendicularly to the chain axis, and slightly curved (Fig. 83). Special setae are thick, heavily silicified and bend in a bell-like curve towards the nearest extremity of the chain (Fig. 85). The terminal setae resemble the normal intercalary setae but they are directed outwards from the terminal valve forming a V-like shape. Resting spores are positioned centrally within the parent cell, with both valves smooth and dome-shaped (Fig. 86).</p> <p>EM: —The valve has a central annulus from which extends a complex pattern of radiating costae, branching dichotomously towards the valve margin and becoming parallel on the valve mantle (Figs 87, 88). Some costae originate from small spirals scattered on the valve face. The costae are often interconnected with transverse short connections. The central annulus is not hyaline but filled with an irregular reticulate pattern, and the only hyaline area on the valve surface is observed around the bases of the setae (Figs 87, 88). The marginal ridge possesses a hyaline rim, often extending into somewhat rectangular-shaped siliceous projections (Figs 87, 89, 90). A rimoportula is present only in terminal valves. It is in the form of a round hole from the internal view and externally appears as a short clublike tube (Figs 90–92). Girdle bands are adorned with transverse fine costae and with a longitudinal rib near one edge (Fig. 93). Common setae are circular in cross-section and ornamented with shark fin-shaped spines arranged in a spiral pattern (Fig. 94). The longitudinal costae extend parallel with the seta axis but can also be arranged in a slight spiral pattern. Transverse costae are found perpendicular to each other and form a regular reticulate ornamentation pattern across the setae. Special setae were not observed in EM.</p> <p>Distinctive features: —Cylindrical cells united in very long and slightly twisted chains. Special, thick intercalary setae often present. Valve face, including central annulus, having a complex ornamentation pattern with transverse connections between branching costae and presence of small spirals. Setae showing a regular reticulate ornamentation pattern.</p></div> 	https://treatment.plazi.org/id/038587FE5157FFF16AE5FB1DDDAEFEC9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5151FFF16AE5FE99DE5CFA6D.text	038587FE5151FFF16AE5FE99DE5CFA6D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros costatus Pavillard 1911	<div><p>Chaetoceros costatus Pavillard (1911: 24) (Figs 95–104)</p> <p>References:— Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988), Jensen &amp; Moestrup (1998), Hernández-Becerril &amp; Flores Granados (1998), Hernández-Becerril &amp; Aké-Castillo (2001), Kooistra et al. (2010), Ishii et al. (2011), Lee et al. (2014a).</p> <p>Synonym: — Chaetoceros adhaerens Mangin.</p> <p>Morphometry: —a.a.: 11–15 μm; p.a.: 21–32 μm.</p> <p>LM: —Cells are arranged in straight, sometimes very long chains. The cells are rectangular in girdle view. There is a single, plate-like chloroplast per cell (Fig. 95). Valve face is flat to slightly concave and possesses four submarginal flattened protuberances, two on each side of the valve positioned close to the valve apices. Sibling cells join by fusion of these protuberances, but also by fusion of sibling setae (Fig. 96). The aperture is very narrow, shaped as a linear thin slit, extending between the protuberances, shorter than the apical axis (Fig. 96). The valve mantle is very low and the girdle often very wide. The edges of the numerous girdle bands are readily visible in LM (Fig. 96). The thin and long intercalary setae originate at the valve margin, cross immediately without a basal part and extend mostly perpendicular to the chain axis or slightly curve towards the end of the chain, diverging variously from the apical plane. The terminal setae are morphologically similar to intercalary ones and curved obliquely towards the chain axis.</p> <p>EM: —The lightly silicified valve face has a distinct pattern of costae radiating from a central or a slightly eccentric large hyaline annulus (Figs 97, 98). In the central part of the valve face, costae branch dichotomously towards the valve edge, whilst in part near the apices costae remain for a certain distance parallel with the apical axis converging towards the setae bases (Fig. 98). Each valve, including the terminal ones, has four protuberances not hyaline, but adorned with parallel costae oriented perpendicularly to the apical axis (Fig. 98). An eccentric, slit-shaped rimoportula bearing an external flattened tube is present only on terminal valves (Figs 99, 100). The marginal ridge is ornamented with a low siliceous hyaline rim (Fig. 97). Setae are circular in cross-section, ornamented with small shaped poroids and shark fin-spines arranged in a spiral pattern (Fig. 101). The girdle bands are ornamented with transverse costae interspaced with hyaline areas. The advalvar bands have a distinct thickened longitudinal rib at one edge (Fig. 102).</p> <p>Resting spores are oval or rounded in shape. The primary valve is dome-shaped and covered with numerous hooked conical spines sometimes joined at their basal part by siliceous vela (Fig. 103). The secondary valve has fewer conical spines at the surface (Fig. 104).</p> <p>Distinctive features: —Cells usually united in long chains. Girdle bands visible in LM. Sibling valves joined by setae and by four submarginal protuberances. Aperture shorter than the apical axis. Valve ornamentation pattern showing parallel costae in area proximal to the valve apices.</p></div> 	https://treatment.plazi.org/id/038587FE5151FFF16AE5FE99DE5CFA6D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5151FFFC6AE5FA65DEC6F929.text	038587FE5151FFFC6AE5FA65DEC6F929.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros curvisetus Cleve 1889	<div><p>Chaetoceros curvisetus Cleve (1889: 55) (Figs 105–116)</p> <p>References:— Hustedt (1930), Cupp (1943), Evensen &amp; Hasle (1975), Hargraves (1979), Rines &amp; Hargraves (1988), Hernández-Becerril</p> <p>(1996), Jensen &amp; Moestrup (1998), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Sunesen et al. (2008),</p> <p>Kooistra et al. (2010), Lee et al. (2014a). Synonyms: — Chaetoceros secundus Schütt, Chaetoceros cochlea Schütt.</p> <p>Morphometry:—a.a.: 11–34 μm; p.a.: 8–30 μm.</p> <p>LM:—Cells united in usually long chains; in pervalvar plane curved or spiral (Fig. 105). Cells are broadly elliptical in valve view and rectangular in girdle view with drawn up valve corners. In each cell there is a single large plate-like chloroplast (Fig. 106). The valve face is markedly concave and the setae emerge from the valve corners immediately crossing each other at their point of origin with a short basal part. The apertures are large and elliptical to circular in shape (Fig. 106). The girdle is usually wide and the mantle is narrow. The setae are long and relatively thin. In girdle view they appear all curved towards the same convex side of the chain (Fig. 105), while in the valve view they are all bent to one side of the apical axis. The intercalary and terminal setae are similar in morphology and orientation.</p> <p>EM: —The valve has a hyaline central annulus with lighter centre encircled with a slightly darker marginal area from which extends a regular pattern of relatively thick and rarely dichotomously branched costae (Fig. 107). The pattern appears more complex towards the valve margin where, in some valves, a number of costae form small spirals. The marginal ridge possesses a low hyaline rim (Fig. 108). A central or slightly eccentric rimoportula is present only in terminal valves. It is internally shaped as a simple slit and externally as a wide flattened tube (Figs 108–110). Girdle bands are adorned with transverse fine ribs alternating with rows of small round poroids (Figs 111, 112). Setae are circular in cross-section, ornamented with small poroids and shark fin shaped spines arranged in a spiral pattern (Fig. 113). The resting spore appears to be perforated with small poroids on the valve surface. Resting spores have unequally vaulted valves with the dome-shaped primary valve and less rounded to almost flat secondary valve. The surface of both valves is smooth (Fig. 114). Both valves of the resting spore bear a silica collar that is in the primary valve perforated by a series of elongated simple fissures (Figs 115, 116).</p> <p>Distinctive features: —Chains curved in pervalvar plane, large oval apertures.All setae curved towards the convex side of the chain. Smooth resting spores with a collar. Valve ultrastructure showing a regular pattern of relatively thick and rarely dichotomously branched costae.</p> <p>Chaetoceros decipiens Cleve (1873: 11) [emend. Li, Boonprakob, Moestrup &amp; Lundholm (2017: 5)] (Figs 117–127) References:— Hustedt (1930), Cupp (1943), Evensen &amp; Hasle (1975), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Jensen &amp;</p> <p>Moestrup (1998), Berard-Therriault et al. (1999), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Sunesen et al. (2008), Li et al. (2017). Synonyms: — Chaetoceros grunowii Schütt.</p> <p>Morphometry: —a.a.: 7–51 μm; p.a.: 8–43 μm.</p> <p>LM: —Cells are united in straight chains, sometimes slightly curved in the apical plane (Fig. 117). There are several ((2)4–10) small discoid chloroplasts present in each cell (Figs 118, 119). The valve face is weakly to strongly concave; the valve corners are sharp and drawn up, touching those of the sibling cell. Apertures are wide and elliptical. The mantle is high, usually with a distinct constriction near the margin. The girdle is usually lower than or equidimensional with the mantle. In cells from field samples there were often observed organic threads projecting from the girdle region (Fig. 118). The setae originate from the valve corners, fuse immediately at the chain margin and then diverge at an angle of ca 30° equally from the chain axis.All the setae are lying in the apical plane. The length of the fused part of the setae appears to be a very variable character with the extent of fusion varying even within a single chain and generally reduced in culture material. In most cases and especially in field samples setae can fuse for up to several times their diameter (Fig. 118), however, they can be also fused only at their point of cross over (Fig. 117). The intercalary setae are very stiff, straight and variable in length. Terminal setae appear slightly thicker than intercalary ones, diverging from cell corners in a wide V-shaped curve. Resting spores were not observed.</p> <p>EM: —The valve has a central annulus from which extends a pattern of radiating costae branching dichotomously towards the valve margin and becoming parallel on the valve mantle (Fig. 120). The hyaline areas between costae are densely perforated with poroids (Figs 120, 122, 124). A small rimoportula, with an internal distinct labiate structure (Figs 123, 124) and a very small external protrusion (Fig. 121), is present only on terminal valves. The marginal ridge is ornamented with a hyaline rim and siliceous projections which extend as fringes from the valve mantle (Fig 120). Projections may become large and slice-shaped in proximity of the valve apices (Fig. 121). These projections, in the intercalary valve, fuse with the corresponding structures of the sibling valve (Fig. 120) to form a hyaline structure that can partially occlude the aperture. Girdle bands are ornamented with transverse ribs alternating with less silicified rows of irregularly scattered poroids (Fig. 125). The setae are polygonal, four- to five-sided (Figs 126, 127). Each side is ornamented with a single straight longitudinal row of large round-oval poroids. The size of poroids varies between 0.3 and 0.7 μm with a density of 14–22 poroids in 10 μm in the proximal and central part of the setae (Fig. 126). Larger poroids (up to 1.1 μm) have been rarely observed near the seta tip. Spines are shark fin-shaped and positioned along the setae ridges (Figs 126, 127).</p> <p>Distinctive features: —Corners of sibling valves touching and forming a large aperture; intercalary setae usually fused for a variable distance. Setae stiff, extended in the apical plane, polygonal in cross section. Valve surface densely perforated with poroids. Rimoportula very small with a labiate structure.</p></div> 	https://treatment.plazi.org/id/038587FE5151FFFC6AE5FA65DEC6F929	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE515CFFFF6AE5F939DF66FD15.text	038587FE515CFFFF6AE5F939DF66FD15.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros didymus Ehrenberg 1845	<div><p>Chaetoceros didymus Ehrenberg (1845: 75) (Figs 128–132)</p> <p>References: — Hustedt (1930), Cupp (1943), Rines &amp; Hargraves (1988) (as Chaetoceros didymus var. didymus) Hernández-Becerril (1991b), Jensen &amp; Moestrup (1998), Berard-Therriault et al. (1999), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Sunesen et al. (2008), Ishii et al. (2011), Lee et al. (2014a).</p> <p>Synonyms: — Goniothecium gastridium Ehrenberg, Chaetoceros gastridium Ehrenberg, Chaetoceros mamillanum Cleve, Chaetoceros didymus var. anglica (Grunow) Gran, Chaetoceros. didymus var. hiemalis Tempere and Peragallo, Chaetoceros didymus var. genuina Gran and Yendo, Chaetoceros didymus f. adriatica Schussnig, Chaetoceros didymus f. singularis Takano.</p> <p>Morphometry: —a.a.: 8–33 μm; p.a.: 9–26 μm.</p> <p>LM: —The cells are united in straight chains (Fig. 128). Cells are rectangular in girdle view with sharp and slightly drawn up corners. There are two large plastids per cell (Fig. 129). Valve face is slightly concave with a prominent hemispherical protuberance in the centre; mantle is low without any visible constriction near its edge. The setae originate at the valve corners and cross over each other at the point outside of the chain margin with a basal part of variable length (Figs 128, 129). The apertures are widely peanut-shaped due to the presence of central protuberances on both sibling valves. The intercalary setae are perpendicular to the colony axis or sometimes slightly curve towards the terminal part of the chain (Fig. 128). In valve view, the setae diverge at about 25–45° from the apical plane (Fig. 130). Terminal setae extend almost parallel to the colony axis (Fig. 128).</p> <p>EM: —The valve is ornamented with a weak pattern of costae radiating from the central annulus located on the protuberance and it is densely perforated with round small poroids, with the exception of the central part around the protuberance (Fig. 131). The valve edge and the setae bases are ornamented with long and branched capilli (Figs 130, 131). The setae are in cross-section four-sided (not shown), each side perforated with a single longitudinal line of small poroids and scarcely distributed larger elongated pores (Fig. 132). Shark fin spines are arranged longitudinally on the ridges.</p> <p>Distinctive features: —Valve face with a prominent hemispherical central protuberance. Valve edge and setae bases ornamented with long capilli.</p></div> 	https://treatment.plazi.org/id/038587FE515CFFFF6AE5F939DF66FD15	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE515FFFFF6AE5FCEDDEEFF929.text	038587FE515FFFFF6AE5FCEDDEEFF929.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros diversus Cleve 1873	<div><p>Chaetoceros diversus Cleve (1873: 9) (Figs 133–141)</p> <p>References: — Hustedt (1930), Cupp (1943), Hernández-Becerril (1996), Moreno Ruiz et al. (1993), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Lee et al. (2014a).</p> <p>Synonyms: — Chaetoceros laevis Leuduger-Fortmorel, Chaetoceros rudis Leuduger-Fortmorel, Chaetoceros diversus var. tenuis Cleve, Chaetoceros diversus var. mediterranea Schröder.</p> <p>Morphometry: —a.a.: 7–14 μm; p.a.: 6–11 μm.</p> <p>LM: —Cells are united in short straight chains of 3–9 cells (Fig. 133). In valve view cells are generally circular, in girdle view rectangular with sharp corners. One chloroplast is present per cell (Fig. 134). The setae originate at the valve corners and fuse immediately at the chain margin without a basal part. The apertures are slit-shaped and very narrow or almost absent (Fig. 134). There are two types of intercalary setae: the common ones and special ones (Fig. 133) showing a different thickness and orientation. Special setae diverge at an angle of about 45° from the chain axis and then curve towards the terminal part of the chain. They become thicker after some length and then taper again towards their ends. Terminal setae extend almost parallel to the chain axis diverging in a U-shaped curve (Fig. 133). All setae of a chain lie in the apical plane.</p> <p>EM: —The valve has a central annulus from which a weak pattern of radiating costae branches dichotomously towards the valve margin (Fig. 135). The area between costae is irregularly perforated with densely scattered small poroids. Valve is face flat or slightly convex, and the mantle is high with a slight constriction near the edge (Fig. 136). Between the valve face and the mantle in most cases there is no discernible marginal ridge, and only sometimes the extensions of the hyaline rim are fused between sibling cells at each edge of the aperture (Fig. 136). Terminal cells have a labiate-shaped rimoportula with a small projection on the outside (Figs 137, 138) Special setae are strongly silicified and ornamented with thick shark fin-shaped spines (Fig. 139). Common intercalary setae have four to five longitudinal or slightly spiral rows of rectangular poroids as well as spines spirally arranged around the seta (Fig. 140). Girdle bands are ornamented with transverse parallel ribs (Fig. 141).</p> <p>Distinctive features: —General shape of the chain, cells with very sharp corners and narrow apertures, setae widely diverging in apical plane, with special thicker intercalary setae.</p></div> 	https://treatment.plazi.org/id/038587FE515FFFFF6AE5FCEDDEEFF929	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE515FFFF96AE5F939DF9EFC65.text	038587FE515FFFF96AE5F939DF9EFC65.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros lauderi Ralfs	<div><p>Chaetoceros lauderi Ralfs in Lauder (1864a: 77) (Figs 142–153)</p> <p>References: — Hustedt (1930), Cupp (1943), Hargraves (1979), Rines &amp; Hargraves (1988), Hernández-Becerril &amp; Flores Granados (1998), Jensen &amp; Moestrup (1998), Sunesen et al. (2008), Kooistra et al. (2010), Ishii et al. (2011).</p> <p>Synonyms: — Chaetoceros weissflogii Schütt.</p> <p>Morphometry: —a.a.: 15–39 μm; p.a.: 27–63 μm.</p> <p>LM: —Cells are united into long straight chains which are slightly twisted around the chain axis (Fig. 142). In valve view cells are circular to elliptical, in girdle view rectangular with sharp corners and pervalvar axis generally longer than the apical axis (Fig. 143). There are numerous (25–45) small chloroplasts present in each cell (Fig. 143). The valve face is flat. The mantle is low without constriction at its edge while the girdle is usually very broad. Intercalary setae emerge from the corners of the valves, fuse without a basal part and immediately diverge in different directions. Apertures are very narrow and slit-like (Fig. 143). Setae are generally straight, extending perpendicular to the chain axis, with some of them curving towards either end of the chain (Fig. 142). In valve view setae diverge from the apical plane at an angle of 30–40°; in some cases one seta is parallel with the apical plane and the other is more or less perpendicular. Terminal setae are morphologically similar to intercalary ones, strongly diverging in a broad Ushaped curve (Fig. 142).</p> <p>EM: —The valve face is ornamented with densely and irregularly distributed anastomosing costae radiating from a relatively large central annulus (Figs 144, 145) and becoming parallel on the valve mantle (Fig. 146). The area between costae is hyaline. The marginal ridge is often ornamented with a very low hyaline rim (Fig. 147). Terminal valves possess a slit-shaped rimoportula (Figs 146, 148) with an external wide flattened tube (Fig. 147). Setae are circular in cross-section, ornamented with small poroids and shark fin-shaped spines arranged in a spiral pattern (Fig. 149). The girdle bands have parallel transverse ribs alternating with less silicified areas perforated by irregularly distributed small poroids (Fig. 150). The resting spores are ornamented with long spines on their primary valve and few long thing capilli on the secondary valve. (Fig 151). The capitate primary valve of the resting spore is constricted at its base and spines which are either completely straight or sharply bent near the tip (Fig. 152). Secondary valve is flat to vaulted, either with smooth surface or ornamented with thin and very long hair-like spines (capilli) which are commonly present in a form of a single ring on the mantle advalvar margin (Fig. 153).</p> <p>Distinctive features: —Elongated cells, very narrow and almost non-existent apertures. Chains slightly twisted around the axis and setae diverging in all directions. Resting spores with long spines on the capitate primary valve and ring of long capilli around the secondary valve mantle.</p></div> 	https://treatment.plazi.org/id/038587FE515FFFF96AE5F939DF9EFC65	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5159FFF96AE5FC7DDEDCFA01.text	038587FE5159FFF96AE5FC7DDEDCFA01.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros messanensis Castracane 1875	<div><p>Chaetoceros messanensis Castracane (1875: 32) (Figs 154–155)</p> <p>References: — Hustedt (1930), Cupp (1943), Evensen &amp; Hasle (1975), Hernández-Becerril (1996), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006).</p> <p>Synonyms: — Chaetoceros furca Cleve, Chaetoceros furca var. macroceros Schröder, Chaetoceros cornutus Leuduger-Fortmorel.</p> <p>Morphometry: —a.a.: 10–37 μm; p.a.: 17–40 μm.</p> <p>LM: —Cells are united in short, straight chains (Fig. 154). Cells are rectangular in girdle view with sharp, drawn up valve corners which touch sibling cells. One chloroplast present per cell (Fig. 154). The valve face is flat to slightly concave; the mantle is low without any constriction at its edge. Intercalary setae originate from the valve corners and fuse immediately without basal part. Apertures are very wide, elliptical to hexagonal (Fig. 155). There are two types of intercalary setae: the thin common ones and thick special ones. Special setae are longer than the common ones, strongly silicified, fuse for about two thirds of their length and then separate again, strongly diverging into a thick and slightly undulated fork. Common setae are thin and in the girdle view equally diverged from the apical axis at an angle of 30–60°. Terminal setae are thin, strongly bent outwards from their point of origin and differ in orientation from each other, one being strongly bent toward the chain (Figs 154, 155).</p> <p>Distinctive feature: —Morphology of the intercalary special setae.</p></div> 	https://treatment.plazi.org/id/038587FE5159FFF96AE5FC7DDEDCFA01	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5159FFFA6AE5F9D1DE31F858.text	038587FE5159FFFA6AE5F9D1DE31F858.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros protuberans Lauder 1864	<div><p>Chaetoceros protuberans Lauder (1864a: 79) (Figs 156–159)</p> <p>References: — Hustedt (1930) (as Chaetoceros didymus var. protuberans), Cupp (1943) (as Chaetoceros didymus var. protuberans), Rines &amp; Hargraves (1988) (as Chaetoceros didymus var. protuberans), Lechuga-Devéze &amp; Hernandez-Becerril (1988), Hernández-Becerril (1991b), Jensen &amp; Moestrup (1998) (as Chaetoceros didymus var. protuberans), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Kooistra et al. (2010), Lee et al. (2014b).</p> <p>Synonym: — Chaetoceros didymus var. protuberans (Lauder) Gran &amp; Yendo.</p> <p>Morphometry: —a.a.: 13–24 μm; p.a.: 22–26 μm.</p> <p>LM: —The cells are united in short and straight chains (Fig. 156). Cells are elliptical in valve view and rectangular in girdle view with sharp and slightly drawn up corners. Valve face is slightly concave with a prominent hemispherical protuberance in the centre (Fig. 156). The intercalary setae arise at the cell corners with a long basal part and cross over each other outside the chain margin (Figs 156, 157). They diverge from the apical axis at a small angle in valve view, and in girdle view they are generally straight or slightly bent towards the chain end (Fig. 156). The apertures are wide and constricted in the centre due to the presence of central protuberances on both sibling valves.</p> <p>EM: —Valves are densely perforated with round small poroids lacking only on the central protuberance (Fig. 158). A hyaline rim is present along the marginal ridge of the valve. The valve mantle is low with a slight constriction near its edge (Fig. 158). The setae are generally four-sided in cross-section, with each side perforated with a single longitudinal line of elliptical poroids. Shark fin-shaped spines are arranged longitudinally on the ridges (Fig. 159).</p> <p>Distinctive features: —Valve face with a prominent hemispherical central protuberance. Absence of siliceous capilli present on the valves of the similar species C. didymus.</p> </div>	https://treatment.plazi.org/id/038587FE5159FFFA6AE5F9D1DE31F858	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE515BFFFB6AE5FF56DC09FD60.text	038587FE515BFFFB6AE5FF56DC09FD60.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros pseudocurvisetus Mangin 1910	<div><p>Chaetoceros pseudocurvisetus Mangin (1910: 350) (Figs 160–161)</p> <p>Bibliography: — Hustedt (1930), Cupp (1943), Fryxell (1978), Rines &amp; Hargraves (1988), Hernández-Becerril (1996), Hernández-Becerril &amp; Flores Granados (1998), Shevchenko et al. (2006), Kooistra et al. (2010).</p> <p>Description: —a.a.: 15–35 μm; p.a.: 16–30 μm.</p> <p>LM: —Cells are united in long, curved or helical chains (Fig. 160). Cells are elliptical in valve view and rectangular in girdle view. In each cell there is a single lobed chloroplast (Fig. 161). The valve face is concave with four protuberances situated along the valve margin, two per each side of the valve positioned close to the valve apices. Each protuberance fuses with the corresponding one on the sibling valve (Fig. 161) forming a narrow oval aperture which is shorter than the cell apical axis (Fig. 161). Intercalary setae originate from the valve corners and fuse immediately without basal part. In girdle view all setae are curved towards the same, convex side of the chain (Fig. 160) while in valve view they are all bent to one side of the apical axis.</p> <p>Distinctive features: —Chains curved in the pervalvar plane. Oval aperture narrower than in the very similar species C. curvisetus.</p> </div>	https://treatment.plazi.org/id/038587FE515BFFFB6AE5FF56DC09FD60	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE515BFFFB6AE5FD72DCF0F8DC.text	038587FE515BFFFB6AE5FD72DCF0F8DC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros socialis Lauder 1864	<div><p>Chaetoceros socialis Lauder (1864a: 77) [emend. Chamnansinp, Li, Lundholm &amp; Moestrup (2013: 1133] (Figs 162–</p> <p>172)</p> <p>References:— Hustedt (1930, as C. radians), Evensen &amp; Hasle (1975, as C. radians), Hargraves (1979), Rines &amp; Hargraves (1988), Jensen &amp; Moestrup (1998), Sunesen et al. (2008), Shevchenko et al. (2008), Kooistra et al. (2010), Degerlund et al. (2012), Chamnansinp et al. (2013).</p> <p>Synonyms: — Chaetoceros socialis f. autumnalis Proschkina-Lavrenko, Chaetoceros socialis f. socialis Proschkina-Lavrenko, Chaetoceros socialis f. radians Proschkina-Lavrenko, Chaetoceros radians Schütt.</p> <p>Morphometry: —a.a.: 9–13 μm; p.a.: 5–13 μm.</p> <p>LM: —Cells are joined in short chains curved in broad girdle view. Each cell usually possesses three curved setae and one long and straight seta which extends towards the concave part of the chain. By connection of the long setae tips short chains join to form large spherical colonies having in their centre the interconnected tips (Figs 162, 163). The cells are elliptical in valve view and rectangular in girdle view with sharp corners. Each cell possesses a single large chloroplast (Fig. 165). The delicate and thin setae originate inside the valve margins and direct outwards, with sibling setae crossing each other after a long basal part thus forming wide hexagonal apertures (Figs 164, 165). In valve view, the orientation of the setae has one pair of sibling setae diverging 30–50° from the apical plane. One member of the second pair curves back around the cell and continuing in the direction of the first pair, and the other being especially elongated and growing toward the colony centre. Resting spores are round in shape, with both valves dome-shaped and spiny (Fig. 164).</p> <p>EM: —The frustule is weakly silicified. Valve face is flat to concave with an inflated central part (Fig. 168); the mantle is low without a constriction near its edge, girdle usually equidimensional with the mantle. The valve is ornamented with a weak pattern of scarcely distributed costae radiating from the central annulus and converging towards the two insertion points of the setae (Figs 167). The setae are circular in cross-section, bearing arrowhead shaped spines arranged in a helicoidal pattern (Fig. 169). Setae are also ornamented with small poroids arranged in a spiral pattern, and with irregularly distributed larger elongated pores (Fig. 169). Both valves of the resting spore are covered with spines over the whole surface and a ring of spines at the margin of the primary valve (Figs 170, 171). The spines appear to be conically shaped and occasionally the longest spines have a minute bifurcation at the tip. The spines vary greatly in length with generally the primary valve spines being much longer than on the secondary valve (Fig. 172).</p> <p>Distinctive features: —Curved chains usually joined in large spherical colonies by connection of the tips of long setae. Delicate and thin setae having a distinct basal part and forming large hexagonal apertures. Resting spores with spines on both valves.</p></div> 	https://treatment.plazi.org/id/038587FE515BFFFB6AE5FD72DCF0F8DC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5165FFC66AE5FF56D8E3FD61.text	038587FE5165FFC66AE5FF56D8E3FD61.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros tortissimus Gran 1900	<div><p>Chaetoceros tortissimus Gran (1900: 122) (Figs 173–182)</p> <p>References:— Ikari (1926), Hustedt (1930), Cupp (1943), Hoppenrath et al. (2009), Shevchenko et al. (2006).</p> <p>Morphometry: —a.a.: 14–21 μm; p.a.: 5–14 μm.</p> <p>LM: —Cells are united in usually long chains that are very strongly twisted around the chain axis in such a way that some sibling valves position themselves perpendicular to each other (Figs 173–175). In valve view cells are broadly elliptical and compressed in the transapical direction, in girdle view they are rectangular with rounded valve corners. Each cell contains a single parietal plate-like chloroplast positioned around the girdle (Fig. 176). The valve face is flat or slightly convex; the mantle is low and sometimes constricted near the margin, girdle equidimensional or higher than the mantle. Long and thin setae originate within the valve margin and slightly direct outwards forming a short basal part, and then cross slightly inside or at the chain margin (Fig. 175). Apertures are hexagonally shaped. Intercalary setae are generally oriented more or less perpendicularly to the chain axis or appear slightly curved (Fig. 173). In valve view they diverge at an equal angle (30–45°) from the apical plane. Terminal setae are thick like the intercalary ones and extend almost parallel to the colony axis in a U-shaped curve (Fig. 173).</p> <p>EM: —The valve has a central hyaline annulus from which extends a complex pattern of densely distributed costae, branching dichotomously towards the valve margin, sometimes forming small dots (Figs 177, 178). The marginal ridge does not have a prominent rim; it is only observable as a thickened edge between the valve face and the mantle. Girdle bands are adorned with transverse fine costae and a slightly thickened longitudinal rib near one edge (Fig. 181). A conspicuous character found in this species is the presence of a large elongated pore on the proximal part of the setae, right after the crossing point (Figs 178–180). Setae are circular in cross-section, ornamented with very small spines and poroids spirally positioned along the seta length (Fig. 182).</p> <p>Distinctive features: —Very strong torsion of the chain. Large elongated pore on the proximal part of the seta.</p></div> 	https://treatment.plazi.org/id/038587FE5165FFC66AE5FF56D8E3FD61	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5166FFC66AE5FD71DF85F905.text	038587FE5166FFC66AE5FD71DF85F905.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros vixvisibilis Schiller	<div><p>Chaetoceros vixvisibilis Schiller in Hustedt (1930: 727) (Figs 183–194)</p> <p>References:— Hustedt (1930), Hernández-Becerril (2010).</p> <p>Morphometry: —a.a.: 8–17 μm; p.a.: 7–25 μm.</p> <p>LM: —Cells are united in straight and usually very long chains, sometimes slightly twisted around the chain axis (Fig. 183). The cells are elliptical in valve view and rectangular to square in girdle view with sharp, slightly drawn up valve corners. The number and shape of chloroplasts is not clear as the cell content often appears fragmented in several smaller parts in field material (Figs 184, 185). The valve face is flat with a slight central inflation; the valve mantle is low with no observable constriction near the margin. The girdle is moderately high. The setae originate at the valve corners and immediately cross each other. Apertures are quite narrow and very slightly constricted in the middle due to the presence of the slight central inflation on the sibling valves (Fig. 185). The setae are straight and usually very long and thin, however, they are very delicate and often found broken in the field samples (Fig. 183). They are generally oriented perpendicular to the chain axis but can be bent more or less towards either chain end. Terminal setae do not morphologically differ from the intercalary ones and either are perpendicular to the chain axis or widely curved forming a U-shape. Resting spores are found very often within the cells displaying a wide range of morphological variation in shape and size (see the description below).</p> <p>EM: —Valves have a very conspicuous pattern with a slightly eccentric hyaline annulus from which costae radiate and mostly bifurcate towards the valve margin (Fig. 186). Some costae are twisted forming small spirals (Fig. 186). Terminal valves show the same basic features, but additionally, have a rimoportula with a labiate structure (Fig. 187). Girdle bands are ornamented with transverse ribs (Fig. 188). Setae are circular in cross-section and ornamented solely with spirally arranged rows of small poroids, lacking any kind of spines or larger pores (Figs 189, 190). The resting spores possess unequal valves. The primary valve is markedly dome-shaped, often with a variable number (1–4) of strong and long spines usually with many dichotomous branches at the tips (Figs 191–194). Secondary valve is smooth, either flat or with a more or less expanded inflation in the centre. The mantle of both valves may be low to relatively high depending on the spore size (Fig. 194).</p> <p>Distinctive features: —Very long chains, setae delicate and straight, often broken. Narrow apertures. Valve ornamentation with costae ends twisted in small spirals. Setae without spines. Resting spores with one to four branching spines on primary valve.</p> <p>Subgenus Bacteriastroidea Hernández-Becerril (1993)</p></div> 	https://treatment.plazi.org/id/038587FE5166FFC66AE5FD71DF85F905	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
038587FE5166FFC06AE5F8DDDC4DF7E3.text	038587FE5166FFC06AE5F8DDDC4DF7E3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetoceros bacteriastroides Karsten 1907	<div><p>Chaetoceros bacteriastroides Karsten (1907: 390) (Figs 195–198)</p> <p>References: — Fryxell (1978), Hernández-Becerril (1993)</p> <p>Morphometry: —a.a.: 9–10 μm; p.a.: 22–30 μm.</p> <p>LM: —Cells are united in short, straight and robust chains (Fig. 195). In valve view cells are nearly circular, in girdle view rectangular with pervalvar axis longer than apical axis. Each cell contains numerous small chloroplasts (Fig. 196). The setae appear to contain some plastid-like material in few of the observed specimens, but it was not possible to determine if these granules indeed contain chlorophyll. The valve face is flat to slightly concave and the mantle is quite high without a constriction near the margin. Each intercalary valve possesses two common, long and robust setae, and four short, thin and strongly spirally undulated setae (Figs 196). Common setae originate at the valve margin on two opposite sides of each valve, and join with sibling setae after a short basal part. They fuse for a rather long distance (ca. half of the valve diameter) and then diverge equally at an angle of ca. 30° from the apical axis, lying in the apical plane. Spiral setae also have a short basal part but they fuse at a single point and then extend perpendicular to the chain axis lying in the valvar plane (Fig. 195). The aperture between adjacent cells is distinct, and appears to be elliptical in shape due to the most visible connection between two long sibling setae. Terminal valve possesses only two long common setae extended in the direction of the chain. The two terminal setae slightly differentiate in the curvature, one being more parallel to the chain axis while the other is first more widely curved and then becomes parallel with the same axis.</p> <p>EM: —The valve face and the mantle are densely perforated with very small poroids in an irregular pattern (Fig. 197). Two sibling intercalary valves were observed with shoehorn-shaped outgrowths arising from the valve margin between setae (Fig. 197). Common setae are circular in cross-section. They are perforated with longitudinal rows of very small poroids running parallel with the seta axis from their basal part throughout the whole length of the seta. After the fused part small spines are found arranged in a spiral pattern around the seta (Fig. 198). Short setae are straight and with few small spines in the proximal part and T-shaped spines in the distal spirally undulated part. The surface of the undulated part is not smooth, but adorned with small silicate nodules. The spiral coils are at first very narrow and become wider in the terminal part (Fig. 198).</p> <p>Distinctive features: —Cell circular in valve view. Shape and orientation of terminal, common and spirally undulated setae.</p></div> 	https://treatment.plazi.org/id/038587FE5166FFC06AE5F8DDDC4DF7E3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Bosak, Sunčica;Sarno, Diana	Bosak, Sunčica, Sarno, Diana (2017): The planktonic diatom genus Chaetoceros Ehrenberg (Bacillariophyta) from the Adriatic Sea. Phytotaxa 314 (1): 1-44, DOI: 10.11646/phytotaxa.314.1.1, URL: http://dx.doi.org/10.11646/phytotaxa.314.1.1
