Cumella croixensis, Petrescu, Iorgu, Chatterjee, Tapas & Schizas, Nikolaos V., 2016

Petrescu, Iorgu, Chatterjee, Tapas & Schizas, Nikolaos V., 2016, New species and new records of Cumacea (Crustacea: Peracarida: Cumacea) from mesophotic reefs of Puerto Rico and U. S. Virgin Islands, Caribbean Sea, Zootaxa 4199 (1), pp. 1-78 : 37-40

Cumella croixensis sp. nov.

( Figs. 15 , 16 )

Material examined. Holotype ovigerous female ( MGAB CUM 1738 ), May 4, 2012, Salt River Canyon , St. Croix , U.S. Virgin Islands, Caribbean Sea, 17°47'12.8040"N, 64°45'30.8160"W, 70 m , paratypes: 1 subadult female ( MGAB CUM 1774 ), Lang Bank, St. Croix , U.S. Virgin Islands, Caribbean Sea 17°50'03.1560"N, 64°28'33.0240"W, 55 m, May 6, 2012, leg. 2012 UPRM-DMS Mesophotic Cruise ; 1 subadult male ( MGAB CUM 1787 ), El Seco, Vieques Island, Puerto Rico, 18°07'24.8520"N, 65°12'05.7600"W, 52–67 m, January 17, 2010, collected during the UPRM-DMS Mesophotic Cruise.

Diagnosis. Carapace smooth (in female), one denticle on dorsal margin, anterior margin of pseudorostrum serrate, ventral margin of carapace serrate in female (only anterior half serrate in male). Few setae on dorsal side of carapace, setae on pereonites 4–5 and pleonites 1–5. Five lateral lenses on ocular lobe in male, five laterals and one central lens on ocular lobe in female. uropodal peduncle 0.73 times last pleonite length in female, 0.78 in male.

Description. Ovigerous female (holotype MGAB CUM 1738).

Body size: 1.76 mm ( Fig. 15 A).

Carapace ( Fig. 15 A). Smooth integument, basis 0.42 times as long as rest of body, 1.62 times as long as high, one medio-dorsal denticle, two setae on posterior end pseudorostrum 0.4 times frontal lobe length, serrate anterior margin, ocular lobe with five lateral and one central lenses, serrate ventral margin, anterior ventral corner with stronger serration.

Pereon, two simple setae on posterior margin of 4th pereonite and one on 5th pereonite.

Pleon, one simple seta on posterior end of first 1–4 pleonites articles and two on the 5th pleonite.

Antenna 1 ( Fig. 15 B). Basal article of peduncle 1.08 times as long as rest of articles together, main flagellum 0.66 times the length of apical article of peduncle, minute accessory flagellum.

Maxilliped 3 ( Fig. 15 C). Basis 0.73 times as long as rest of together, serrate medial margin with a distal plumose seta, two pappose longer setae on outer process; merus 3.6 times as long as ischium, one short plumose seta on medial margin, one plumose longer seta on outer margin; carpus 0.72 times as long as merus, one short plumose seta on medial margin, one pappose longer seta on outer margin; propodus 1.38 times as long as carpus, two pappose setae on medial margin, one plumose seta on outer margin; dactylus 0.62 times propodus length, terminal robust seta as long as dactylus; slender exopod.

Pereopod 1 ( Fig.15 D). Basis 0.54 times as long as rest of articles together, one spine and three simple setae on medial margin; merus 1.07 times as long as ischium, one simple seta on medial margin of both articles, carpus 2.36 times as long as merus, two simple setae on medial margin; propodus 0.75 times as long as carpus, two simple setae on medial distal margin; dactylus 0.56 times as long as propodus, terminal robust seta 1.15 times dactylus length; slender exopod.

Pereopod 2 ( Fig. 15 E). Basis 0.56 times rest of pereopod length, long simple seta on medial margin; merus 3 times as long as ischium, one simple seta on medial margin, carpus as long as merus, two short plumose setae on outer margin, one simple stout seta on medial margin; dactylus 2 times propodus length, two simple short setae on medial margin, two subterminal and a terminal robust seta 1.26 times propodus length; slender exopod.

Pereopod 3 ( Fig. 15 F). Basis 1.22 times rest of pereopod length; merus 1.8 times as long as ischium, one simple short seta on medial margin; carpus 1.7 times as long as merus, one simple short seta on outer margin; propodus 0.7 times as long as carpus; dactylus 0.33 times as long as propodus, fused with terminal robust seta.

Pereopod 4 ( Fig. 15 G). Basis 0.76 times rest of pereopod length, merus 2.4 times ischium length, one simple short seta on medial margin; carpus 2.16 times as long as merus; propodus 0.54 times as long as carpus, one simple short seta on outer margin; dactylus 0.36 times propodus length, fused with terminal robust seta.

Pereopod 5 ( Fig. 15 H). Basis 0.72 times rest of pereopod length; merus 1.43 times as long as ischium, one simple seta on medial margin; carpus 2.7 times as long as merus; propodus 0.66 times as long as carpus; dactylus 0.28 times as long as propodus, fused with terminal robust seta.

Uropod ( Fig. 15 I). Peduncle 0.73 times last pleonite length, 1.05 times endopod length; exopod 0.9 times endopod length, terminal robust seta 1.11 times exopod length; one subterminal seta on medial margin of endopod, terminal robust one 0.9 times endopod length.

Description. Subadult male (paratype MGAB CUM 1787).

Body size, 1.58 mm ( Fig. 16 A).

Carapace ( Fig. 16 A). Rugous integument, 0.52 times as long as rest of articles together, one denticle on dorsal margin of frontal lobe, nine simple setae on dorsal margin; pseudorostrum 0.24 times frontal lobe length, serrate anterior margin, five lenses on ocular lobe, short serration on ventral margin.

Antenna 1 ( Fig. 16 B). Basal article of peduncle shorter than rest of articles combined length.

Maxilliped 3 ( Fig. 16 C). Basis 0.37 times as long as rest of articles together, one short pappose seta on medial margin, two longer ones one outer process; merus 3.33 times as long as ischium, one simple plumose seta on medial margin, one much longer pappose seta on outer margin; carpus 1.16 times as long as merus, three plumose setae on medial margin, one longer on outer margin; propodus 1.14 times as long as carpus, two pappose setae on medial margin, one shorter plumose one on outer margin; dactylus 0.35 times as long as propodus terminal robust seta as long as dactylus; incompletely developed exopod.

Pereopod 1 ( Fig. 16 D). Basis 0.69 times rest of articles combined length, two simple setae on medial margin; merus as long as ischium, one simple seta on medial margin of ischium and on both margins of merus; carpus 2.21 times as long as merus, three simple setae on medial margin, one on outer distal margin; propodus 0.8 times as long as carpus, two simple setae on both margins; dactylus 0.65 times as long as propodus, terminal robust seta as long as dactylus; incompletely developed exopod.

Pereopod 2 ( Fig. 16 E). Basis 0.58 times as long as rest of articles together; merus 2.6 times as long as ischium, one simple seta on medial margin of merus; carpus 1.15 times as long as merus, two simple setae on both margins; dactylus 1.5 times as long as propodus, two simple short setae on medial margin, one subterminal seta on both margins, one terminal robust seta 1.2 times dactylus length; incompletely developed exopod.

Pereopod 3 ( Fig. 16 F). Basis 1.04 times as long as rest of articles together; merus 1.25 times as long as ischium, one simple seta on medial margin of both articles; carpus 1.2 times as long as merus; propodus 1.42 times as long as carpus, one simple short seta on outer margin; dactylus 0.23 times as long as propodus, robust terminal seta; incompletely developed exopod.

Pereopod 4 ( Fig. 16 G). Basis 0.83 times as long as rest of articles together; merus 1.5 times as long as ischium; carpus 2.22 times as long as merus; propodus 0.65 times as long as carpus, one simple short seta on both margins; dactylus 0.38 times propodus length, terminal robust seta longer than dactylus; incompletely developed exopod.

Pereopod 5 ( Fig. 16 H). Basis 0.45 times as long as rest of articles together; merus 1.71 times as long as ischium; carpus 2.41 times as long as merus, one simple short seta on both margins of carpus; propodus 0.65 times as long as carpus; dactylus 0.26 times propodus length, robust terminal seta 2 times dactylus length.

Uropod ( Fig. 16 I). Peduncle 0.78 times last pleonite length, as long as endopod; exopod 0.73 times as long as endopod, one simple short seta on proximal article outer margin, one simple short seta on distal article, terminal robust seta as long as exopod; endopod with one simple seta, one subterminal one and two compose pedunculate setae on medial margin, terminal robust seta 0.57 times endopod length.

Etymology. The species bears the name of type locality, Saint Croix, U.S. Virgin Islands.

Remarks. The new species, Cumella croixensis is similar to C. portoricensis sp. nov. from Puerto Rico with one denticle on the carapace and serrate ventral margin of carapace, pereopod 2 with dactylus with two setae on medial margin, short uropods. It differs with: 1) ocular lobe with six lenses in C. croixensis vs. five in C. portoricensis ; 2) dorsal denticle on carapace immediately behind frontal lobe (only in female) vs. on frontal lobe; 3) serrate anterior margin of pseudorostrum vs. smooth; 4) pereopod 1 with setae on medial margin of basis to dactylus vs. carpus to dactylus; 5) pereopod 2 with simple setae on medial margin of basis and merus and two plumose ones on outer margin of carpus vs. none; 6) uropodal peduncle without setae vs. peduncle with one seta on outer margin and two on medial one.

Figures

FIGURE 15. Cumella croixensis sp. nov. Holotype female. A, body, lateral view; B, antenna 1; C, maxilliped 3; D, pereopod 1; E, pereopod 2; F, pereopod 3; G, pereopod 4; H, pereopod 5; I, uropod. Scale bars: A, 0.5 mm; B – I, 0.1 mm.

FIGURE 16. Cumella croixensis sp. nov. Paratype subadult male. A, body, lateral view; B, antenna 1; C, maxilliped 3; D, pereopod 1; E, pereopod 2; F, pereopod 3; G, pereopod 4; H, pereopod 5; I, uropod. Scale bars: A, 0.5 mm; C, 0.05 mm; B, D – I, 0.1 mm.