taxonID	type	description	language	source
B676932DFF85081C67E5FE9AFAACCF2F.taxon	diagnosis	Diagnosis. Chondrillida in which the choanocyte chambers are tubular, branched and wide mouthed. Larvae are incubated disphaerulae (a larval form found only in Halisarca) with simple undifferentiated histology and cilia of uniform length. Skeleton is composed of fibrillar collagen only, there are no fibrous or mineral elements present; ectosomal and subectosomal collagen is highly organised and structurally diversified (Ereskovsky et al. 2011).	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF85081067E5FD77FB07CE9E.taxon	description	(Figs 2 – 10, Table 1) Synonymy. Halisarca dujardini var. magellanica, Topsent, 1901; Thiele, 1905; Burton, 1929, 1932, 1940. Original description. Halisarca dujardini var. magellanica, Topsent, 1901, p. 44 – 45.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF85081067E5FD77FB07CE9E.taxon	materials_examined	Type material. Holotype: RBINS-POR. 034 — 4 fragments (alcohol), Antarctic Expedition of the Belgica 1897 – 99, sample n ° 47, Torrent Bay, Londonderry Island, Antártica Chilena Province, Chile (55 ° 03 ' S – 69 ° 23 ' W), intertidal, coll. M. Racovitza, 18. xii. 1897. Material examined. RBINS-IG 32232 - POR. 8798 (Fragment: MNRJ 8798), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 20 m depth, coll. Ph. Willenz & E. Hajdu, 24. ii. 2005. RBINS-IG 3 2232 - POR. 8888 (Fragments: MNRJ 8888, MHNG 89996), Piedra Lile, Quellón, Chiloe Province, Chile (43 ° 10 ’ 58.60 ” S – 73 ° 38 ’ 27.20 ” W), 16 m depth, coll. E. Hajdu & Ph. Willenz, 04. iii. 2005. RBINS-IG 32235 - POR. 10753 (Fragments: MNRJ 10753, MHNG 90093), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 13 m depth, coll. Ph. Willenz & E. Hajdu, 07. v. 2007. RBINS-IG 32 235 - POR. 10827 (Fragments: MNRJ 10827, MHNG 90161), Reñihué Fjord, Palena Province, Chile (42 ° 30 ' 48.06 " S – 72 ° 37 ' 49.74 " W), 13 m depth, coll. Ph. Willenz & E. Hajdu, 23. v. 2007. RBINS-IG 32238 - POR. 12918 (Fragments: MNRJ 12918, MHNG 90252), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ' 43.32 " S – 72 ° 35 ' 54.90 W), 26 m depth, coll. Ph. Willenz & J. Biro, 01. ii. 2009. RBINS-IG 32238 - POR. 12920 (Fragments: MNRJ 12920, MHNG 90254), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ' 43.32 " S – 72 ° 35 ' 54.90 W), 26 m depth, coll. Ph. Willenz & J. Biro, 01. ii. 2009. RBINS-IG 32238 - POR. 12921 (Fragments: MNRJ 12921, MHNG 90255), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 10 m depth, coll. Ph. Willenz, 01. ii. 2009. RBINS-IG 32238 - POR. 12922 (Fragments: MNRJ 12922, MHNG 90256), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 10 m depth, coll. Ph. Willenz, 01. ii. 2009. Additional material not observed in Electron Microscopy. MNRJ 8797 (Fragment: RBINS-IG 32232 - POR. 8797), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 20 m depth, coll. Ph. Willenz & E. Hajdu, 24. ii. 2005. MNRJ 8892 (Fragment: RBINS-IG 32232 - POR. 8892), Piedra Lile, Quellón, Chiloe Province, Chile (43 ° 10 ’ 58.60 ” S – 73 ° 38 ’ 27.20 ” W), 16 m depth, coll. E. Hajdu & Ph. Willenz, 04. iii. 2005. RBINS-IG 32238 - POR. 12933 (Fragment: MNRJ 12933), Reñihué Fjord, Palena Province, Chile (42 ° 30 ’ 20.70 ” S – 72 ° 46 ’ 29.70 ” W), 30 m depth, coll. Ph. Willenz & J. Biro, 08. ii. 2009. External morphology. Polymorphic sponge. The first morphotype, 0.2 to 10 mm thick, corresponding to the type specimen (Topsent 1901), is encrusting and massive with a slimy surface, slippery to the touch (morphotype 1, Figs 2 A – 2 D). The consistency is gelatinous and elastic. When growing on mussel banks or under overhangs, it forms stretched filamentous outgrowths of different lengths and shapes " dripping " downward, resulting in propagules bearing a discrete osculum at their end (Figs 2 A – 2 C). Ostia are microscopic and barely visible. The second morphotype is thinly encrusting, without propagules but with the same viscous surface and consistency (morphotype 2, Fig. 2 E). Both morphotypes are found on vertical to horizontal hard substrates or under overhangs. The third morphotype is " bushy ", 1 to 5 cm high, made of grouped digitations, each with obvious pores (ostia) and always ending with a clearly visible osculum. The surface is velvety and the consistency is more brittle and less elastic than morphotypes 1 & 2. It is found growing mainly on vertical substrates (morphotype 3, Figs 2 F & 2 G).	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF85081067E5FD77FB07CE9E.taxon	description	Colour. All three morphotypes are bright pink when exposed to the light and usually ivory or whitish when hidden under overhangs. Anatomy. The ectosome has a thickness varying from 80 to 280 µm in morphotypes 1 & 3 and reaches 900 µm in morphotype 2 (Figs 3 A – 3 I). The structure of the ectosome is similar in all three morphotypes and is composed of a superficial layer made of flat extensions of exopinacocyte cell bodies, which themselves are located under an intermediary complex collagenous layer and connect to the surface of the sponge by thin processes (Figs 4 A – 4 C, 4 E & 4 F). Exopinacocyte cell bodies are distant from each other and are only tightly joined at the level of their superficial extensions. The external membrane of the exopinacocytes is covered by a thin glycocalyx varying from 30 to 150 nm (Fig. 4 F). The collagenous layer shows two regions: its outward side consists of a loose and diffuse unorganized structure 1 to 6 µm thick, whereas its inward side consists of interlaced collagen fibrils forming dense tracts 2 to 25 µm, which are in contact with the rest of the ectoderm lying underneath (Figs 4 C & 4 D). The thickness of the collagenous layer ranges from 4 µm to 30 µm with varying internal composition. In the arborescent morphotype, regularly spaced invaginations of the basal region of the collagenous layer extend into the mesohyl (Figs 3 I & 4 B). Both regions of the collagenous layer include few scattered spherulous cells and bacteria (Figs 3 C & 3 I, 4 A & 4 B). The choanosome is typical of all Halisarca species previously described in the literature, with irregularly shaped, elongated and curved choanocyte chambers (30 to 180 µm long x 10 to 40 µm wide), aquiferous canals and a mesohyl containing a variety of cell types, bacteria and collagen bundles (Figs 3 A – 3 C, 3 E – 3 I & 5 A). No difference in abundance or size of choanocyte chambers is observed between morphotypes 1 & 3 (Figs 3 B, 3 C & 3 F – 3 H). Chambers are less abundant in morphotype 2 (MNRJ 10753) and occur deeper in the sponge, under a 900 µm thick ectosome (Fig 3 D). In some sections, choanocyte chambers are located radially around several thin, probably inhalant, canals 4 to 16 µm in diameter (Fig 3 F). Larger canals, most likely exhalant, occur less frequently in the choanosome (Figs 3 A & 3 D). In semi-thin sections stained with methylene blue / azure II and basic fuchsine, the mesohyl stains pink to purplish-red, indicating the abundance of collagen. TEM sections reveal the granular structure of the mesohyl; abundant electron dense granules 19 to 93 nm in diameter amalgamate in a fuzzy loose matrix crossed by collagen fibrils and bundles (Figs 7 D, 9 A, 10 D & 10 G). Cytology. Exopinacocytes (Figs 4 A – 4 C, 4 E & 4 F) are " T-shaped " in transverse sections with an extremely thin superficial extension situated at the tip of a narrow projection emerging from the cell body and connecting cells to each other through inter-cellular junctions (Figs 4 E & 4 F). Cell bodies (2.5 to 8.6 µm in diameter), with a basal nucleolated nucleus, are anchored in the mesohyl below the complex collagen layer of the ectosome. Choanocytes (Figs 5 A – 5 E) are long and cylindrical (10.5 – 14.5 µm x 4.0 – 4.5 µm), with abundant basal pseudopodial extensions. The cytoplasm contains many electron translucent vacuoles, abundant larger electron dense basal inclusions and an apical nucleolated nucleus. An irregular periflagellar sleeve, sometimes longer than the microvilli of the collar, surrounds the base of the flagellum. Endopinacocytes (Figs 6 A – 6 C) are flat cells lining the canals of the aquiferous system. Their shape is thin and flat with a central oval nucleolated nucleus. Basopinacocytes were not observed. Archaeocytes (Fig. 7 A) are around 7.0 to 15.0 µm in size, occur infrequently throughout the mesohyl and have a classical amoeboid shape with pseudopodia. The nucleolated nucleus (3.2 to 3.9 µm in diameter) is spherical and located centrally. The cytoplasm is dense with phagosomes and electron-dense vacuoles of variable sizes ranging from 150 to 470 nm. Lophocytes (Figs 7 B – 7 D) are abundant elongated cells (around 1.5 x 14.0 µm) with a tuft of collagen fibrils emerging from their posterior end. The nucleus is either located in the anterior (Fig. 7 B) or the posterior (Fig. 7 C) side of the cell. The cytoplasm is dense, contains phagosomes and small electron-dense inclusions (140 to 960 nm). Spherulous cells are of three types, two of which were never previously described in Halisarca. Spherulous cells Type I (Fig. 7 E) are globular oval cells (6.5 – 8.2 x 9.0 – 10.6 µm in diameter) packed with large dense osmiophilic homogeneous membrane bound inclusions of variable diameter (1.1 to 4.8 µm) squeezing a central nucleolated nucleus, and a relatively small remaining cytoplasmic volume. They are the most abundant mesohylar cells in the ectosome and the choanosome of all investigated specimens. Spherulous cells Type II (Fig. 7 F) are large, bulbous and spherical (7.8 – 8.9 x 7.8 – 11.6 µm in diameter) with large inclusions of variable diameter (1.3 to 4.2 µm) composed of two distinct parts: a large crescent-shaped osmiophilic portion encompasses a smaller elliptical less osmiophilic region, giving a " chestnut aspect " to these inclusions. The cytoplasm volume is also minimized and the central nucleus is nucleolated. These cells do not occur in all specimens but, when present, are common in the choanosome (Table 1). Spherulous cells Type III (Fig. 7 G) are more spherical (5.8 – 9.4 x 7.1 – 11.7 µm) than the two previous types and contain heterogeneous inclusions (1.1 – 2.1 x 2.2 – 3.3 µm) characterized by a rough internal texture with a more osmiophilic periphery. The cytoplasm volume is larger than in Type I and Type II, with a spherical nucleolated nucleus. These cells are rare, found only in the choanosome and are not observed in all specimens (Table 1). Granular cells (Fig. 7 H) are oval shaped cells (5.5 – 63 x 7.1 – 11.3 µm) with a nucleolated nucleus and spherical homogeneous osmiophilic inclusions of variable size, but smaller than in spherulous cells Type 1 (0.6 x 1.6 – 2.3 µm in diameter). These cells are infrequent, occur only in the choanosome and are not present in all specimens (Table 1). Microgranular cells (Fig. 8 A) are amoeboid cells (7.5 – 10.6 x 4.2 – 7.5 µm), distinct from granular cells by their anucleolated nucleus and the abundance of electron dense spherical or elliptical inclusions of smaller size (0.5 – 0.8 x 0.2 µm) contained in the cytoplasm. Small phagosomes and a developed endoplasmic reticulum are also present. Microgranular cells occur in all specimens examined but are not abundant, and are found randomly in the choanosome. Rhabdiferous cells (Figs 8 B – 8 E) are amoeboid in shape (4.5 – 10.7 x 3.3 – 7.6 µm) with short pseudopodia. The nucleolated nucleus is relatively large and spherical (2.1 – 3.6 µm in diameter). The cytoplasm is filled with osmiophilic elliptical membrane bound inclusions (0.7 – 1.7 x 0.4 – 0.7 µm), which include one or two less dense spherical sub-inclusions (rhabdites). Rhabdiferous cells are numerous in all specimens examined and occur equally in the ectosome and the choanosome where they are even occasionally found within choanocyte chambers (Figs 8 D & 8 E). Pocket cells (Figs 9 A – 9 G) are amoeboid in shape, of variable size, (6.3 – 8.8 x 8.9 – 16.9 µm) characterized by one or several large " pockets " formed by junction of long and thin pseudopodial extensions engulfing portions of the mesohyl that often include bacteria. As the size and the number of pockets progressively increase, the volume of the cytoplasm decreases until it becomes a thin layer surrounding a nucleolated nucleus (1.7 – 2.1 x 2.2 – 3.3 µm). The final content of the pockets has the same density as the mesohyl. The cytoplasm contains phagosomes and abundant electron dense and electron translucent small inclusions. Bacteriocytes (Figs 10 A – 10 C) are roundish massive cells (10.0 – 18.3 µm in diameter) with pseudopodial extensions and packed with large bacteria of a single morphotype (Type B 1). The cytoplasm is dense and the anucleolated nucleus is squeezed at the periphery of the cell. Bacteria are rod-shaped up to 4.5 µm long and 1.2 µm wide and are isolated from the cytoplasm by a membrane. All present a thick electron dense cytoplasm with a thin central electron translucent filamentous nucleoid. Bacteriocytes do not occur in all specimens, are infrequent and appear randomly in the choanosome. Extracellular symbiotic bacteria (Figs 10 D – 10 F). Two other morphotypes of bacteria are found extracellularly, evenly distributed in the mesohyl, spanning from the outward collagenous layer of the ectosome to the entire choanosome (Types B 2 and B 3). Type B 2 is abundant, rod-shaped and reaches 910 nm in length and 380 nm in diameter. The cytoplasmic matrix is homogeneous and electron dense. The nucleoid is more electron translucent, with a central rod surrounded by filamentous material. The cell wall is thick and covered with discrete fimbriae. Type B 3 is spiral-shaped and has a thick cell wall. The length is undetermined in TEM since an entire longitudinal section is unlikely obtained. The width ranges 200 to 470 nm. The cytoplasmic matrix is clear and the nucleoid is homogeneous and electron dense. Type B 3 is much less frequent, occurs in a minority of specimens and is found exclusively in the choanosome (Table 1). Reproduction. One of both specimens collected in March 2005 and two out of four collected in February 2009 contained oocytes in different stages of development.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF85081067E5FD77FB07CE9E.taxon	distribution	Distribution. Halisarca magellanica is known from austral Chile (56 ° – 54 ° S), Argentina and Uruguay (56 ° – 34 ° S) and Malvinas Islands (Desqueyroux & Moyano 1987). Habitat. Halisarca magellanica is commonly found at depths ranging from 1 to 26 m, on mussels beds at shallow depths or covering rocks below 10 m.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF85081067E5FD77FB07CE9E.taxon	description	Phylogenetic analysis. Partial cox 1 sequences were determined for five specimens of H. magellanica (RBINS 10827 = morphotype 1; RBINS 10753 = morphotype 2; RBINS 12918, 12920 and 12921 = morphotype 3) and were found to be identical. Phylogenetic analysis of these data along with previously published sequences of H. dujardini, H. caerulea, H. harmelini, Halisarca sp. GW 3298 from the Red Sea and selected outgroups showed H. magellanica forming a sister group to all other analysed Halisarca sequences except for H. harmelini (Fig. 19). The cox 1 sequence of H. magellanica was 9.1 – 9.7 % different from the other Halisarca species.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF89080967E5FC3BFBD0CB32.taxon	materials_examined	Material examined. Holotype: RBINS-IG 32236 - POR. 10803 (Fragments: MNRJ 10803, MHNG 90139), Reñihue Fjord, Palena Province, Chile (42 ° 31 ' 55.02 " S – 72 ° 35 ' 30.72 " ' W), 3 m depth, coll. Ph. Willenz & E. Hajdu, 22. v. 2007. Paratypes: RBINS-IG 3 2235 - POR. 10754 (Fragments: MNRJ 10754, MHNG 90094), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 43.32 ” S – 72 ° 35 ’ 54.90 ” W), 14 m depth, coll. Ph. Willenz & E. Hajdu, 07. v. 2007. RBINS-IG 3 2236 - POR. 10757 (Fragments: MNRJ 10757, MHNG 90097), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 43.32 ” S – 72 ° 35 ’ 54.90 ” W), 13 to 16 m depth, coll. Ph. Willenz & E. Hajdu, 07. v. 2007. RBINS-IG 3 2238 - POR. 12917 (Fragments: MNRJ 12917, MHNG 90251), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ' 43.32 " S – 72 ° 35 ' 54.90 " W), 26 m depth, coll. Ph. Willenz & J. Biro, 01. ii. 2009. RBINS-IG 32238 - POR. 1 2919 (Fragments: MNRJ 12919, MHNG 90253), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ' 43.32 " S – 72 ° 35 ' 54.90 " W), 26 m depth, coll. Ph. Willenz & J. Biro, 01. ii. 2009. RBINS-IG 32238 - POR. 12924 (Fragments: MNRJ 12924, MHNG 90258), Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ' 43.32 " S – 72 ° 35 ' 54.90 " W), 26 m depth, coll. Ph. Willenz & J. Biro, 01. ii. 2009. Additional paratypes not observed in Electron Microscopy. RBINS-IG 32 232 - POR. 8795 (Fragment: MNRJ 8795) Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 20 m depth, coll. Ph. Willenz & E. Hajdu, 24. ii. 2005. RBINS-IG 32236 - POR. 9193 (Fragment: MNRJ 9193), Estero Farquhar, Bernardo Fjord, Capitán Prat Province, Chile (48 ˚ 29 ' 18,70 " S – 74 ˚ 12 ' 25,70 " W), 4 m depth, coll. V. Häusssermann & G. Försterra, 29. iii. 2005. RBINS-IG 32236 - POR. 9214 (Fragments: MNRJ 9214, Estero Farquhar, Bernardo Fjord, Capitán Prat Province, Chile (48 ˚ 29 ' 18,70 " S – 74 ˚ 12 ' 25,70 " W), 5 m depth, coll. V. Häusssermann & G. Försterra, 29. iii. 2005. RBINS-IG 32236 - POR. 9215 (Fragments: MNRJ 9215, Tempano Fjord, Capitán Prat Province, Chile (48 ° 42 ' 59.70 " S – 74 ° 00 ' 18.80 " W), 8 m depth, coll. V. Häusssermann & G. Försterra, 26. iii. 2005. RBINS-IG 32233 - POR. 9961 (Fragments: MNRJ 9961, MHNG 90662), Isla Lavinia, Última Esperanza Province, Chile (49 ° 00 ' 48.10 " S – 74 ° 58 ' 37.50 " W), 4 m depth, coll. Ph. Willenz & L. Atwood, 13. iii. 2006. RBINS-IG 32 238 - POR. 12923 (Fragments: MNRJ 12923, Liliguapi Island, Comau Fjord, Palena Province, Chile (42 ° 09 ’ 44.23 ” S – 72 ° 35 ’ 42.99 ” W), 11 m depth, coll. Ph. Willenz & J. Biro, 1. ii. 2009.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF89080967E5FC3BFBD0CB32.taxon	description	External morphology. Polymorphic sponge. The first morphotype corresponding to the holotype is the most frequently encountered. It consists of an encrusting wrinkled mat, up to 2 cm thick, composed of ridges and short digitations with well-defined oscula (morphotype 1, Figs 11 A – 11 D). The surface is slimy with clear and evenly spread ostia. The consistency is resistant to tearing. The second morphotype is represented by individuals of tubular form varying in length, with a single and sometimes stretched out osculum (morphotype 2, Figs 11 E – 11 H). Colour. Both morphotypes are light brown when exposed to the light and beige when hidden under overhangs. Anatomy. The ectosome varies from 80 to 250 µm in thickness (Figs 12 A, 12 B, 12 D, 12 E & 12 G – 12 H). On its outside, it is delimited by a superficial layer made of plane extensions of exopinacocytes connecting through thin processes with their cell bodies, which are located under a thick complex collagenous layer (Figs 13 B & 13 C). No glycocalyx covers the external membrane of the exopinacocytes in any of the observed samples. A complex collagenous layer contains two distinct regions: its outward side has a loose and diffuse unorganized structure, 1 to 14 µm thick; its inward side, 3 to 5 µm thick, is made of collagen fibrils arranged in dense tracts, which are in contact with the underlying choanosome (Figs 13 A, 13 C & 13 E). The global thickness of the collagenous layer is not consistent and ranges between 6 to 19 µm among the samples, but without any particular widening. Spherulous cells are scattered in the collagenous layer and are abundantly concentrated in the ectosome. They are more dispersed in the choanosome (Figs 12 A – 12 I). Symbiotic bacteria are also present from the outermost collagenous layer to the deepest regions of the mesohyl. The choanosome includes typical elongate and convoluted choanocyte chambers (50 to 260 µm long x 20 to 60 µm wide) surrounded by numerous aquiferous canals of various diameters (Figs 12 A – 12 I). The mesohyl is very lax and remarkably clear, lacking dense granules (Figs 14 – 17), but contains collagen tracts (Figs 12 D – 12 F) and different wandering cell types at low density. Cytology. Exopinacocytes (Figs 13 A – 13 E) are " T-shaped " in transverse section. Their cell bodies (2.8 to 6.7 µm in diameter), with basal nucleolated nuclei, are deeply rooted under the complex collagenous layer, and connect with thin flake-like superficial extensions, revealed in SEM, through outstretched projections (Figs 13 A – 13 C). Inter-cellular junctions between superficial extensions connect exopinacocytes to each other (Fig. 13 D). Choanocytes (Figs 14 A – 14 D) are stretched and cylindrical with a roughly pyramidal base (6.9 to 10.5 µm long x 2.1 to 8.3 µm wide) provided with basal pseudopods extending toward the mesohyl. The cytoplasm comprises electron dense inclusions and phagosomes, mainly concentrated on the basal side of the cell, and an apical nucleus. A periflagellar sleeve surrounds the base of the flagellum. Endopinacocytes (Figs 15 A & 15 B) are flat with a prominent oval nucleus and constitute the walls of the canals. Basopinacocytes were not observed. Archaeocytes (Fig 16 A) are few and have a conventional amoeboid shape (6.2 – 8.0 µm) with a spherical nucleolated nucleus (3.7 to 4.3 µm in diameter). The cytoplasm is dense with phagosomes and vacuoles of different densities varying from 270 to 670 nm in diameter. Lophocytes (Figs 16 B & 16 C) are elongated (ranging 2.3 x 9.6 µm) with tufts of collagen fibrils emerging from their posterior side or surrounding them. The nucleus is located in the anterior part of the cell. The cytoplasm is dense, contains phagosomes and small osmiophilic inclusions (330 x 730 nm). Spherulous cells of two different types are distinguished in TEM (Figs 13 A & 13 C). Spherulous cells Type I (Figs 16 D & 17 C) are oval cells (7.8 – 10.9 x 11.5 – 12.0 µm in diameter) with short pseudopodial extensions. Large dense osmiophilic homogeneous membrane-bound inclusions of variable diameter (1.0 to 3.8 µm) squeeze the central nucleolated nucleus, leaving exiguous space for a cytoplasm containing phagosomes and small electron translucent vesicles (100 to 200 nm). They are the most abundant cells in the mesohyl. Spherulous cells Type III (Figs 13 A, 16 E – 16 G & 17 F) are large cells (5.0 – 7.4 x 8.8 – 10.6 µm) with irregular shape. Large inclusions (0.8 to 2.0 µm in diameter) of porous texture with a denser periphery occupy most volume of the cytoplasm that contains large phagosomes, except for the cells occurring near the exopinacocytes (Fig. 16 G). These cells are common and mainly located in the upper part of the ectosome and occur less often in the choanosome; they are not found in all specimens examined (Table 1). Granular cells (Fig. 16 H) are round cells (4.5 – 7.0 x 6.7 – 7.7 µm in diameter) with homogeneous spherical inclusions of variable size and density (0.6 – 1.0 x 1.6 – 3.6 µm in diameter) and large phagosomes. These cells are found in the choanosome but do not occur in all specimens (Table 1). Rhabdiferous cells (Figs 17 A & 17 B) are irregularly shaped cells (7.9 – 4.0 x 6.3 – 1.7 µm) with short pseudopodia. The nucleus is spherical and anucleolated (1.7 – 2.6 µm in diameter). The cytoplasm contains abundant osmiophilic elliptical membrane bound rhabdites (up to 1.3 µm in length and 0.8 µm in diameter), which include a less dense spherical sub-inclusion. Rhabdiferous cells occur in the ectosome and in the choanosome, where they are either free in the mesohyl or occasionally enclosed within choanocyte chambers and even larvae. Pocket cells (Figs 17 C – 17 H) are amoeboid cells (6.3 – 13.3 x 3.9 – 7.2 µm) with long pseudopods extending actively around the cell to phagocytize components of the mesohyl, including cells from other types and bacteria, forming large " pockets ". The nucleolated nucleus is round to ovoid (2.9 to 4.0 x 2.6 to 3.5 µm). These cells occur everywhere in the sponge, from the choanosome to the ectosome where they appear to be more developed. Their membrane is folded in many thin and puffed layers, forming small electron translucent microvesicles located at the periphery of the cell. Some pocket cells with numerous pockets and smaller electron translucent vacuoles are crossing the collagen layer to be rejected from the sponge as they are found at the surface of the exopinacocytes. Extracellular symbiotic bacteria (Figs 18 A – 18 E) of three different morphotypes occur in the mesohyl. The nomenclature used here corresponds to the one used above for H. magellanica. Type B 1 is absent. Type B 2 is rod shaped and reaches 1.9 µm in length and 0.3 µm in diameter with an electron dense thick wall and an electron translucent cytoplasmic matrix. The electron translucent nucleoid presents a central rod surrounded by filamentous material. Type B 2 occurs only in H. desqueyrouxae sp. nov. morphotype 2 (Table 1). Type B 3 is spiral-shaped and thick walled, its width reaches 0.4 to 0.5 µm. The cytoplasmic matrix is clear and the nucleoid is electron dense. Type B 3 occurs in the choanosome of all specimens of both morphotypes where it is evenly distributed. Type B 4 is larger in diameter than Type B 2 (1.1 to 1.4 x 0.5 µm), and has a more ovoid shape and a wrinkled capsule. No central rod appears in the clear nucleoid. This type was found in only one specimen of each morphotype (Table 1). Types B 2 and B 4 are exclusively found in the collagenous layer of the ectosome where they are frequent. Reproduction. One of the three specimens collected in early February 2009 contained embryos and prelarvae. Larvae appeared in two out of the three specimens collected in May 2007 (Figs 12 A, 12 C & 12 H).	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF89080967E5FC3BFBD0CB32.taxon	distribution	Distribution. Halisarca desqueyrouxae sp. nov. is presently known from Chilean Patagonia (42 ° S). Habitat. Halisarca desqueyrouxae sp. nov. is commonly found at depths ranging from 3 to 26 m, on mussel beds at shallow depths or covering rocks exposed to the light and under overhangs below 10 m.	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
B676932DFF89080967E5FC3BFBD0CB32.taxon	etymology	Etymology. The specific epithet is a tribute to Dr. Ruth Desqueyroux-Faúndez who inspired our first sponge collections in Chilean Patagonia and actively participated in several expeditions in that region. Phylogenetic analysis. Partial cox 1 sequences were determined for seven specimens of H. desqueyrouxae sp. nov. (RBINS 10803, 10757, 12917, 12919, 12924 and 12923 = morphotype 1; RBINS 10754 = morphotype 2) and were found to be identical. Phylogenetic analysis placed H. desqueyrouxae sp. nov. as a sister group to H. dujardini, but revealed 2.3 % difference between their cox 1 sequences (Fig. 19).	en	Willenz, Philippe, Ereskovsky, Alexander V., Lavrov, Dennis V. (2016): Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia. Zootaxa 4208 (6): 501-533, DOI: 10.11646/zootaxa.4208.6.1
