Cumella tricornuta, 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 : 17-18

Cumella tricornuta sp. nov.

( Fig. 6 )

Material examined. Holotype: subadult female ( MGAB CUM 1726 ), St. John , U.S. Virgin Islands, Caribbean Sea, 18°13'18.6960"N, 64°40'33.4560"W, 54 m, May 8, 2012 ; paratypes: 1 subadult female ( MGAB CUM 1727 ), St. John , U.S. Virgin Islands, Caribbean Sea, 18°13'18.6960"N, 64°40'33.4560"W, 54 m, May 8, 2012 ; 1 subadult female ( MGAB CUM 1728 ), El Seco, Puerto Rico, Caribbean Sea, 18°07'24.8520"N, 65°12'05.7600"W; 1 manca ( MGAB CUM 1786 ), St. John , U.S. Virgin Islands, Caribbean Sea, 54 m, May 8, 2012, 18°13'18.6960"N, 64°40'33.4560"W, collected during the 2012 UPRM-DMS Mesophotic Cruise.

Diagnosis. Carapace with three strong dorsal denticles on ocular lobe, ocular lobe with five lenses, short siphon, ventral margin of carapace serrate; uropodal peduncle 1.07 times last pleonite length with serrate ventral margin, one short seta on serrate medial margin of uropod.

Description. Subadult female (holotype MGAB CUM 1726).

Body size: 1.26 mm ( Fig. 6 A).

Carapace ( Fig. 6 A, B), 0.3 times pereon and pleon combined length, 1.5 times as long as high, three strong dorsal denticles on the ocular lobe, pseudorostral lobe 0.15 frontal lobe length, ocular lobe with five lenses, short siphon, serrate ventral margin.

Antenna 1 ( Fig. 6 C, D). Basal article 1.05 times rest of articles combined length, median article 1.37 times as long as apical article, accessory flagellum 1-articled. Main flagellum 1.75 times apical peduncle article, two long aesthetascs.

Maxilliped 3 ( Fig. 6 E). Basis 0.85 times as long as rest of articles together, one plumose seta on medial margin, two long plumose ones on outer margin; merus 1.57 times as long as ischium, one plumose seta on outer margin; carpus as long as merus, one short plumose seta on medial margin, one longer one on outer margin; propodus 1.27 times as long as carpus, two pappose setae on medial margin, one plumose seta on outer margin; dactylus 0.57 times propodus length, terminal robust seta as long as dactylus; slender exopod.

Pereopod 1 ( Fig. 6 F). Basis 0.62 times rest of articles combined length, outer margin serrate in distal half, one simple seta on median margin; merus 1.7 times as long as ischium, one seta on median margin; carpus 1.17 times as long as merus, serrate margins, one simple seta on medial margin; propodus as long as carpus, one simple seta on medial margin; dactylus 0.5 times propodus length, terminal stout seta 1.2 times dactylus length; slender exopod.

Pereopod 2 ( Fig. 6 G). Basis 0.57 times as long as rest of articles together; merus 5 times as long as ischium, one simple seta on outer margin; carpus 1.4 times as long as merus, two stout setae on medial margin; dactylus 2.5 times propodus length, one simple short seta on medial margin, two subterminal setae and one terminal robust seta as long as dactylus; slender exopod.

Pereopod 3 ( Fig. 6 H). Basis 0.62 times as long as rest of articles together; merus 1.66 times as long as ischium, carpus 1.2 times as long as merus; propodus as long as carpus, dactylus 0.25 times propodus length, terminal robust seta two times dactylus length.

Pereopod 4 ( Fig. 6 I). Basis 0.53 times as long as rest of articles together; merus 1.28 times as long as ischium; carpus 1.77 times as long as merus, propodus as long as carpus; dactylus 0.31 times as long as propodus, terminal stout seta 1.4 times dactylus length.

Pereopod 5 ( Fig. 6 J). Basis 0.34 times as long as rest of articles together; merus 1.66 times as long as ischium; carpus 1.6 times as long as merus, propodus 0.87 times carpus length, dactylus 0.28 times propodus length.

Uropod ( Fig. 6 K). Peduncle 1.07 times last pleonite length, as long as endopod length, two simple short setae on outer margin, serrate medial margin, exopod 0.93 times endopod length, terminal robust seta 0.89 times exopod length, one short seta on serrate medial margin of endopod, one subterminal and terminal stout seta 0.53 times endopod length.

Etymology. The species is named from the Latin tres, three and cornutus, horned, in reference to the three strong, horn-like denticles on the carapace.

Remarks. Cumella tricornuta sp. nov. resembles C. achimae Petrescu, Chatterjee & Schizas, 2013 also from Puerto Rico ( Petrescu et al., 2013) in the denticles on the ocular lobe, whereas the main differences are: 1) C. tricornuta sp. nov. has denticles on ocular lobe of carapace vs. denticles on ocular lobe and dorsal side of carapace in C. achimae , 2) uropodal endopod with two medial setae in C. tricornuta vs. three in C. achimae .

Cumella (Cumella) tricornuta sp. nov. is also similar to C. (Cumewingia) biserrata Petrescu, 2002 from Belize ( Petrescu, 2002) in the denticles on the ocular lobe, the main differences are: 1) Cumella (Cumella) tricornuta sp. nov. has one row of denticles vs. two rows of denticles in C. (Cumewingia) biserrata , and 2) the ocular lobe with five lenses in C. (Cumella) tricornuta vs. seven in C. (Cumewingia) biserrata .

Figures

FIGURE 6. Cumella tricornuta sp. nov. Holotype subadult female. A, body, lateral view; B, carapace, detail of anterior part; C, antenna 1; D, antenna 1, detail; E, maxilliped 3; F, pereopod 1; G, pereopod 2; H, pereopod 3; I, pereopod 4; J, pereopod 5; K, uropod. Scale bars: A, 0.5 mm; B, D, 0.05 mm; C, E – K, 0.1 mm.