Hemicyclops cyanus, Kim & Wang & Ivanenko, 2025
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publication ID |
https://doi.org/10.3897/zookeys.1260.168539 |
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publication LSID |
lsid:zoobank.org:pub:850D7FC4-63D2-4B85-A802-E2AD3E5FBAA2 |
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DOI |
https://doi.org/10.5281/zenodo.17642929 |
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persistent identifier |
https://treatment.plazi.org/id/C3CB7246-CF55-5527-A094-1F366EB27830 |
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treatment provided by |
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scientific name |
Hemicyclops cyanus |
| status |
sp. nov. |
Hemicyclops cyanus sp. nov.
Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3
Type material.
Holotype: One dissected ♀ mounted on 3 slides ( HNIBRIV 18791 ) GoogleMaps .
Type locality.
20°38'03.1"N, 116°49'30.5"E, Lagoon of Dongsha Atoll GoogleMaps , Pratas Islands, the South China Sea, depth 10 m, 12 October 2017. Collector: V. N. Ivanenko.
Host.
Galaxea fascicularis (Linnaeus, 1767) ( Scleractinia , Euphylliidae ).
Etymology.
The name is derived from the Greek “cyan” (meaning “blue-green”), referring to the blue-green colour of the holotype.
Description.
Female. Body (Fig. 1 A View Figure 1 ) rather narrow, with a vivid blue-green colour all over. Prosome 732 × 477 μm, consisting of the cephalothorax and second to fourth pedigerous somites, with nearly parallel lateral margins. Cephalothorax 436 μm long, wider than long, with projected and acutely pointed posterolateral corners. The second and third pedigerous somites bearing a membranous fringe along their posterodorsal margin.
Urosome (Figs 1 B View Figure 1 , 2 A View Figure 2 ) 5 - segmented. First urosomal somite (fifth pedigerous somite) 163 μm wide, with a membranous fringe along the posterodorsal margin. The genital double-somite 1.08 times longer than wide (330 × 309 μm); its anterior 40 % wing-like, expanded laterally, tapering towards posterolaterally, with a blunt apex. Genital aperture (Fig. 1 D View Figure 1 ; indicated by arrowhead) positioned dorsolaterally at the proximal region of the expanded part. Each posterolateral region of this expanded part bearing a small copulatory pore (Fig. 2 B View Figure 2 ; indicated by arrowhead). The narrower posterior 60 % part of the double-somite bearing 1 small tubercle on each lateral margin and 1 plate-like ventral organ (Fig. 2 B View Figure 2 ) on the anteroventral region, with 7 pores along the distal margin. The genital double-somite and three abdominal somites with a membranous fringe along their posteroventral margin. The three abdominal somites are short, measuring 45 × 106, 30 × 103, and 36 × 102 μm, respectively. The anal somite bears a large anal aperture.
Spermatophore complex (Fig. 1 B, C View Figure 1 ), formed by the fusion of the original pair of spermatophores, is strongly modified, with a tube-like medial region encircling the urosome and wing-like lateral expansions, each bearing lateral and posterior apices. Each spermatophore internally contains bubble-like transparent globules of irregular sizes; a space is present lateral to the spermatophore.
Caudal rami (Fig. 1 E View Figure 1 ) widely separated from each other; each ramus 1.15 times longer than wide (45 × 39 μm), bearing two transverse rows of fine setules on the inner side, one minute proximal setule (rudimentary seta I) on the outer margin, and six setae (setae II – VII). Seta IV (outer distal seta) proximally modified as a spine tipped with a unilaterally pinnate seta.
Rostrum small, triangular, with a blunt posterior apex.
Antennule (Fig. 2 D View Figure 2 ) 354 μm long, 7 - segmented; armature formula: 4, 14, 6, 3, 4 + aesthetasc, 2 + aesthetasc, and 7 + aesthetasc; fifth to terminal segments each with 2, 1, and 4 pinnate setae, respectively; all other setae naked; aesthetascs thin, setiform.
Antenna (Fig. 2 E View Figure 2 ) 4 - segmented, consisting of the coxobasis and 3 - segmented endopod; coxobasis with 1 large seta at the mediodistal region, 3 patches of several setules on the margins; first endopodal segment slightly shorter than coxobasis, bearing 1 spinulose seta on the inner margin and setules or spinules on both margins; second endopodal segment expanded mediodistally (but lacking a digitiform projection), armed with 4 setae (the second proximal seta ornamented with spinules along the inner margin) and several spinules on the inner margin; third endopodal segment wider than long, 24 × 27 μm, subquadrate, bearing 7 setae, one of them spinulose, the others (including 4 geniculated ones) naked.
Labrum (Fig. 2 F View Figure 2 ) broad, with a row of spinules along the posterior margin.
Labium (Fig. 2 G View Figure 2 ) bearing a row of fine spinules along the anterior margin, 1 tooth at each side of the anterior margin, and 5 spinules on the ventral surface near the anterior margin.
Mandible (Fig. 2 H View Figure 2 ) armed distally with 1 stout spine bearing 2 rows of 3 denticles, 1 flabelliform spine, and 2 pinnate setae.
Maxillule (Fig. 2 I View Figure 2 ) distally bilobed; smaller inner lobe with 3 setae, one of them spiniform; larger outer lobe with 5 pinnate setae.
Maxilla (Fig. 2 J View Figure 2 ) 2 - segmented; syncoxa (proximal segment) with 2 spinulose, spiniform setae of equal length, one of them bearing 1 small subsidiary seta at the proximal region; basis (distal segment) with 1 naked ventral seta, distal projection tipped with 3 unequal spines (one of them bearing 2 spinules), 1 spinulose seta, and 1 large, flabelliform spine.
Maxilliped (Fig. 3 A View Figure 3 ) consisting of the syncoxa, basis, and 2 - segmented endopod; syncoxa (first segment) with 2 large, equal setae, one of them feebly pinnate, the other bearing several spinules; basis (second segment) longest, armed with 2 large spinulose setae at the apex of the projected proximal third and ornamented with about 17 setae at the mediodistal region, one of these spinules separated from the others (Fig. 3 B View Figure 3 ); first endopodal segment (third segment) small, unarmed; second endopodal segment (Fig. 3 C View Figure 3 ) forming a long claw, proximally bearing 1 strong spine bearing 4 denticles, 2 naked setae, and 1 small spine bearing 1 setule subdistally.
Legs 1 (Fig. 3 D View Figure 3 ), 2 (Fig. 3 E View Figure 3 ), 3, and 4 (Fig. 3 G View Figure 3 ) biramous, with 3 - segmented rami. The intercoxal plate bearing setules in leg 1 and spinules in legs 2–4. The inner coxal seta is large, stiff, and spiniform in legs 2–4. Leg 3 is similar to leg 2, except bearing 4 spines and 2 setae on the third endopodal segment (Fig. 3 F View Figure 3 ). The outer seta on the basis is large in legs 1 and 4, but small in legs 2 and 3. The mid-distal margin of the basis is ornamented with setules in leg 1 but with spinules in legs 2–4. The inner distal spine on the basis of leg 1 is large, extending to the distal margin of the second endopodal segment. The inner distal margin of the basis of leg 1 has a row of spinules near the base of the inner distal spine. The inner surface of the basis of legs 2–4 bears several spinules. The inner distal process of the third endopodal segment of legs 2–4 is unequally bifurcated. The distal seta on the third endopodal segment of leg 1 is small and naked. The distal flagellum is found on 5 distal spines in leg 1 and 2 distal spines in legs 2–4.
Armature formula for legs 1-4 as follows:
Leg 5 (Figs 1 D View Figure 1 , 3 H View Figure 3 ) 2 - segmented; protopod (proximal segment) wider than long, articulated from somite, armed with 1 long, slender, pinnate distodorsal seta and ornamented with setules and spinules near the base of the seta; exopodal segment 3.37 times longer than wide (118 × 35 μm), curved near the middle, armed with 3 spines and 1 pinnate seta, and ornamented with spinules along the outer and inner margins. The spine on the outer margin is naked, 51 μm long; the outer distal spine is 58 μm long; the distal seta is 55 μm long; the large inner distal spine is 82 μm long, slightly curved, bearing long, brush-like setules along approximately the proximal half of the inner margin.
Leg 6 not visible in dorsal view of genital aperture (Fig. 2 D View Figure 2 ).
Male. Unknown.
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.
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