Spongicoloides zhoui, Zhao & Xu & Yang & Qiu, 2021

Zhao, Yu, Xu, Ting, Yang, Weidi & Qiu, Jian-Wen, 2021, A new species of the deep-sea shrimp genus Spongicoloides (Decapoda: Spongicolidae) from the South China Sea, Zootaxa 5005 (3), pp. 276-290 : 279-285

publication ID	https://doi.org/ 10.11646/zootaxa.5005.3.3
publication LSID	lsid:zoobank.org:pub:6013E601-8FAF-4CA4-BFC5-DB30D0670482
persistent identifier	https://treatment.plazi.org/id/03F17C5A-B74C-FF96-FF2B-FCC2AE78B46C
treatment provided by	Plazi
scientific name	Spongicoloides zhoui
status	sp. nov.

Treatment

Spongicoloides zhoui sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:889C072B-5EFC-44B8-87A8-460C56B0E14B

Spongicolodes novaezelandiae Chen et al., 2016 View in CoL

Type material. Holotype ( TMBC030847 ): ovigerous female, PCL 11.3 mm, TCL 15.1 mm, TBL 37.4 mm, inside a Euplectella sponge, depth 855 m, Zhenbei Seamount , South China Sea, 152.2144′ N, 11631.3269′ E, 2 May 2018 . Allotype ( TMBC030848 ): male, PCL 7.5 mm, TCL 10.4 mm, TBL 26.4 mm, paired with holotype inside the same sponge. Both type specimens are deposited in the Tropical Marine Biodiversity Collections of the South China Sea ( TMBC), Chinese Academy of Sciences .

Diagnosis. Rostrum compressed, horizontal or slightly upturned, terminating with large sharp tooth; dorsal margin armed with 7–8 teeth; ventral margin with 1 subterminal tooth; ventrolateral ridge each with 1–3 lateral teeth. Carapace with dorsum moderately inflated in ovigerous female and concave in male; cervical and branchiostegal groove distinct; spines present on pterygostomial region, postorbital region and posterior region of cervical groove; pterygostomial margin produced anteriorly, rounded, each with 3–5 small spines; fifth somite with 2–4 small posteroventral teeth; sixth somite with or without minute teeth on midline and lateral surface. Telson suboval, with 6–8 spines on each dorsolateral ridge; lateral margins each with 1 proximal submarginal spine and 6–7 lateral spines; posterior margin with 9 spines. Cornea of eye globular; eyestalk armed with 1–2 minute spines. Second and third maxillipeds without exopod. Scaphocerite subquadrangular, lateral margin slightly concave, armed with 4–7 teeth. Fixed finger of third pereiopod armed with row of 1–4 small teeth on distoventral margin; palm and ischium smooth, without teeth. Dactylus of fourth and fifth pereiopods biunguiculate with unguis slightly curved. Uropodal exopod broader than endopod, lateral margin with 7–13 teeth.

Description of holotype female. Rostrum ( Figs. 2 View FIGURE 2 , 3A, 3B View FIGURE 3 ) compressed, narrowly triangular in dorsal view, slightly upturned, about 0.34 times length of PCL, reaching to mid-length of second segment of antennular peduncle, terminating with large sharp tooth; dorsal margin armed with 8 teeth, with most proximal at level of anterior orbital margin; ventral margin armed with 1 subterminal tooth; laterally unarmed; ventrolateral ridge merging into orbital margin, armed with 3 small teeth on left side and 2 small teeth on right side.

Carapace ( Figs. 2 View FIGURE 2 , 3A View FIGURE 3 ) thin, with postcervical dorsum moderately inflated; cervical and branchiostegal groove distinct; antennal spine small, acute; pterygostomial margin produced anteriorly, rounded with 4 small spines on left side and 3 small spines on right side, and several spines situated posterior to them; postorbital region armed with a row of 4 large spines; groups of spines scatters on posterior region of cervical groove and rostral base.

Sixth thoracic sternite ( Fig. 3I View FIGURE 3 ) with paired triangular plates, ventral surface concave. Seventh thoracic sternite with paired broad subrectangular plates. Eighth thoracic sternite with paired trapezoidal plates, anteroventral surface concave.

Pleonal somites ( Figs. 2 View FIGURE 2 , 3F, 3G View FIGURE 3 ) smooth, glabrous. Pleura of first to fifth somite broadly rounded. First somite shortest, divided into two sections by distinct transverse carina, anterior section deeply depressed, partly covered by posterior section of carapace. Second and third somite both with faint transverse groove. Second to fourth somite each with an articular knob. Fifth somite ( Fig. 3G View FIGURE 3 ) with 2 small posteroventral teeth. Sixth somite with 2 minute teeth on midline and 1 minute lateral tooth on right side; posteroventral margin ending in a small tooth; posterior margin smooth. Pleonal sternites unarmed.

Telson ( Fig. 3D View FIGURE 3 ) suboval, about 2.1 times longer than greatest width, slightly constricted proximally; dorsolateral carinae conspicuous, each with 8 posteriorly directed spines; lateral margin slightly convex, each armed with 1 proximal submarginal spine and 6 lateral spines; posterior margin rounded, armed with 9 spines and fringed with long plumose setae.

Eyes ( Fig. 4A View FIGURE 4 ) well-developed; cornea globular, light brown in live specimen (grayish-white after fixed in ethanol); eyestalk short, widened distally, armed with 1 dorsal and 1 mesial minute spines.

Antennular peduncle ( Fig. 4B View FIGURE 4 ) reaching to middle of scaphocerite; proximal segment distinctly longer than distal two segments combined, bearing small, subacute stylocerite; second segment less than half-length of proximal segment, bearing two small spines mesiodistally; distal segment shorter than second article, unarmed. Flagella slender, about 2.8 times peduncle length.

Antenna ( Fig. 4C View FIGURE 4 ) with broad scaphocerite, suboval, about 2.0 times longer than wide; lateral margin slightly concave, not setiferous, armed with 7 large teeth; mesial margin convex; both mesial and distal margins with long plumose setae; dorsal surface with 2 distinct longitudinal carinae. Basicerite stout, bearing 3 large sharp spines on distolateral margin, 3 (left) or 2 (right) minute spines on ventrodistal margin, and 2 minute spines on ventral surface proximally. Carpocerite unarmed, reaching to proximal segment of antennular peduncle. Flagellum 2.4 times as long as PCL.

Mandible ( Fig. 4D View FIGURE 4 ) robust, with well-developed 3-segmented palp; distal segment densely setose marginally, subequal to second segment in length; second segment subquadrangular, with several simple setae at distolateral angle; proximal segment short, without setae. Molar and incisor processes separated, molar surface smooth, without tooth; incisor with 2 stout distal teeth followed by 4 small sharp teeth on mesial margin.

Maxillule ( Fig. 4E View FIGURE 4 ) with small feebly setose palp; upper lacinia broad, distally truncate with 7 slender spines and numerous simple setae; lower lacinia rounded, with numerous simple setae distally.

Maxilla ( Fig. 4F View FIGURE 4 ) with tapering palp bearing simple setae laterally and distally; both coxal and basal endites deeply bilobed, with numerous simple setae; scaphognathite well-developed, about 4.0 times longer than broad, fringed with long plumose setae along margins, anterior lobe larger than posterior lobe.

First maxilliped ( Fig. 4G, H View FIGURE 4 ) with 2-segmented endopod, bearing long plumose setae; distal segment ( Fig. 4H View FIGURE 4 ) broad, with a slender distal spine; proximal segment broad, subquadrangular, 2 times longer than distal segment; basal endite large, rounded anteriorly with slightly concave outer margin bearing dense fringe of simple setae; coxal endite bilobed bearing numerous simple setae; epipod well-developed, subequally bilobed with rounded lobes; exopod well-developed, flagellum-like, bearing long plumose setae distolaterally.

Second maxilliped ( Fig. 4I View FIGURE 4 ) with 7-segmented endopod, last two segments curved backward; dactylus triangular, fringed with dense simple setae on distodorsal margin; propodus subquadrangular, bearing a dense fringe of simple setae on dorsal margin and mesial surface; carpus short, widened distally, with tuft of dorsodistal simple setae; merus straight, longest, subequal to length of dactylus plus propodus, bearing a fringe of sparsely distributed simple setae on mesial margin; ischium and basis not fused, both with simple setae on mesial margin; coxa with oval epipod laterally, bearing a podobranch, arthrobranch present; exopod absent.

Third maxilliped ( Fig. 4J View FIGURE 4 ) with 7-segmented slender endopod; all segments with dense fringe of simple setae on mesial margin; dactylus tapering distally, about 3.8 times longer than proximal width; propodus 1.6 times longer than dactylus; carpus slightly longer than propodus; merus 1.4 times longer than carpal length; ischium robust, subequal to merus in length; basis shortest, rounded and fused with coxa; coxa with small suboval epipod, arthrobranch present; exopod absent.

First pereiopod ( Fig. 5A View FIGURE 5 ) slender, shortest among all five pereiopods, extending distal margin of scaphocerite, each segment with sparse setae on margins; chela slender, palm subcylindrical about 3.2 times longer than central width, fingers about 0.5 times of palm length; fingers and distodorsal margin of propodus with tufts of setae; carpus longest, about 2.7 times longer than palm; merus about 0.8 of carpus length; ischium about 0.4 times of merus length; basis and coxa short, unarmed, epipod absent.

Second pereiopod ( Fig. 5B View FIGURE 5 ) similar to first, but longer and stronger, exceeding distal margin of scaphocerite by length of chela, each segment with sparsely distributed setae on margins; chela slender, palm subcylindrical about 4.6 times longer than central width, fingers about 0.5 times of palm length terminating in hooked unguis; fingers and distodorsal margin of propodus bearing tufts of setae; carpus 1.8 times longer than palm; merus about 0.9 times of carpus length; ischium about 0.5 times of merus length; basis and coxa short; epipod absent.

Third pereiopod ( Fig. 5C, D, E View FIGURE 5 ) largest and longest, exceeding distal margin of scaphocerite by length of chela; chela slender, palm subcylindrical about 3.5 times longer than central width; dactylus about 0.6 times of palm length, terminating in hooked acute unguis crossing tip of fixed finger, bearing tufts of long setae distally, occlusal margin sharply edged, with large blunt tooth slightly proximal to mid-length; fixed finger terminating in strongly curved acute unguis, with short row of 3 (left) or 4 (right) small teeth on distoventral margin and tufts of long setae laterally and ventrally, occlusal margin forming narrow facet distal to excavation accommodating proximal tooth on dactylus; carpus triangular, narrowing proximally, about 0.5 times of palm length, with 2 subtriangular protuberances at dorsomesial distal angle and 1 subtriangular protuberance at ventromesial distal angle; merus about 0.9 times of palm length; ischium about 0.5 times of palm length; basis and coxa short, unarmed, epipod absent.

Fourth and fifth pereiopods ( Fig. 6A–C View FIGURE 6 ) similar, long and slender, each segment with sparse setae on margins; dactylus ( Fig. 6C View FIGURE 6 ) biunguiculate with unguis slightly curved, ventral unguis shorter than dorsal unguis, with 2 small accessory teeth ventrally; propodus not subdivided, about 0.4 of carpus length, armed with ventral row of 20 movable spines; carpus longest, unarmed; merus about 0.8 times of carpus length, unarmed; ischium about 0.4 times of merus length, unarmed; coxa and basis short and stout, unarmed.

First pleopod ( Fig. 6D View FIGURE 6 ) uniramous, second to fifth biramous ( Fig. 6E View FIGURE 6 ). First pleopod ( Fig. 6D View FIGURE 6 ) smallest, with dense long plumose setae along margins; ramus subequal to length of protopod. Second pleopod ( Fig. 6E View FIGURE 6 ) with protopod shorter than rami, bearing ovipositing setae on dorsal and ventral margins; mesial surface with ridge bearing ovipositing setae. Third to fifth pleopods similar, decreasing in size posteriorly; protopod of fourth and fifth pleopods lacking mesial surface ridge and ovipositing setae.

Uropod ( Fig. 3D View FIGURE 3 ) with protopod short, robust with an acute posterolateral spine. Exopod suboval, about 0.8 times of telson length, lateral margin feebly convex, with 13 (left) or 11 (right) teeth on lateral margin; dorsal surface with 2 weak longitudinal ridges on outer half, mesial margins with long plumose setae. Endopod oval, subequal to length of exopod, unarmed on lateral margin; dorsal surface with 1 weak longitudinal ridge; posterior and mesial margins fringed with long plumose setae.

Holotype female carrying 83 eggs ( Fig. 2 View FIGURE 2 ), average size 1.5 x 1.2 mm.

Branchial formula summarized in Table 2.

Description of allotype male. Body size substantially smaller than female ( Fig. 2 View FIGURE 2 ). Rostrum ( Fig. 3C View FIGURE 3 ) nearly horizontal, reaching to mid-length of second segment of antennular peduncle, terminating in large sharp tooth; dorsal margin armed with 7 teeth; ventral margin armed with 1 tooth subdistally; ventrolateral ridge armed with 1 (left) or 2 (right) minute teeth. Carapace ( Figs. 2 View FIGURE 2 , 3C View FIGURE 3 ) less spinose and slightly thicker than in female, with dorsum slightly concave near cervical groove; cervical and hepatic grooves distinct; antennal spine small, acute; pterygostomial margin with 5 (left) or 4 (right) spines. Sixth thoracic sternite ( Fig. 3J View FIGURE 3 ) narrower than in female; Second to fourth pleura each with an articular knob; fifth pleura ( Fig. 3H View FIGURE 3 ) with 4 (left) or 3 (right) posteroventral teeth. Telson ( Fig. 3E View FIGURE 3 ) with 2 conspicuous dorsolateral carinae, each armed with 6 posteriorly directed spines; lateral margins each with 1 proximal submarginal spine and 7 (left) or 6 (right) lateral spines; posterior margin with 9 spines and fringed with long setae. Eyestalk armed with 1 minute spine. Scaphocerite with 4 (left) or 5 (right) lateral teeth. Fixed finger of third pereiopod ( Fig. 5F View FIGURE 5 ) with 2 (left) or 1 (right) small teeth on distoventral margin. Dactylus of fourth and fifth pereiopods biunguiculate with unguis slightly curved, ventral unguis shorter than dorsal unguis. Protopod of uropod ( Fig. 3E View FIGURE 3 ) with 2 (left) or 1 (right) small acute posterolateral spines; exopod with 9 (left) or 7 (right) teeth on lateral margin, broader than endopod.

Etymology. The new species Spongicoloides zhoui was named in honour of Prof. Huaiyang Zhou from Tongji University for organizing the research cruise.

Colour. In freshly collected specimens, body and appendages translucent white; cornea light brown; ovary and eggs pink ( Fig. 2 View FIGURE 2 ). After fixation in 95% ethanol, whole specimens lost transparency and turned pale white.