Eudorella suluensis, Akiyama, Tadashi & Gamô, Sigeo, 2012

Akiyama, Tadashi & Gamô, Sigeo, 2012, The cumacean Genus Eudorella (Crustacea: Peracarida) from Japanese Waters, Northwest Pacific, and E. suluensis sp. nov. from the Sulu Sea, Indo-West Pacific, Zootaxa 3319, pp. 1-56 : 50-52

Eudorella suluensis sp. nov.

( Fig. 35 )

Material examined. Holotype, juvenile female, 4.4 mm, dissected (NSMT-Cr 22166), western slope of the Sulu Sea, Philippine, 08°06.36´N, 118°26.49´E – 08°07.04´N, 118°26.06´E, 688–693 m (KH-02-4, St. 7B), 23 November 2002.

Description. Holotype; juvenile female ( Fig. 3 ). Body weakly calcified. Carapace length 0.20 times total body length, 1.4 times width, latter being subequal to depth; upper front corner with a few tubercles ( Fig. 35 C) and a bundle of setae; frontal margin markedly serrated; lower end of antennal notch close behind frontal margin, succeeded by a narrow gap without teeth; inferior margin with 13 teeth, the most anterior one prominent and directed forward. Pereon length 1.0 times carapace length. Pleon length 0.58 times total body length; dorso-posterior end of 5th pleonite with no long setae.

Antenna 1 ( Fig. 35 D) 3rd article of peduncle subequal in length to 2nd, with 3 plumose setae and 1 simple seta on outer margin, 4 plumose setae on inner margin; main flagellum longer than 2nd article of peduncle, with 3 simple setae on outer margin of 1st article; accessory flagellum shorter than 1st article of main flagellum. Antenna 2 ( Fig. 35 E) with a plumose seta on lower margin and 3 plumose setae on outer margin. Maxilliped 1 with 5 branchial lobules. Maxilliped 2 ( Fig. 35 F) basis much shorter than combined length of ischium, merus and carpus, with 4 setae on inner margin. Maxilliped 3 ( Fig. 35 G) basis 0.9 times distal articles combined, with 8 and 5 plumose setae on inner margin and ventral surface, respectively; ischium with a spine on inner margin; carpus with 8 plumose setae on inner margin.

Pereopod 1 ( Fig. 35 H) basis length 0.6 times distal articles combined, with plumose setae on both inner and outer margins, and 2 robust spiniform setae on ventral surface; propodus 1.2 times carpus and 1.8 times dactylus. Pereopod 2 ( Fig. 35 I) basis length 0.65 times length of distal articles combined; carpus 1.4 times merus and 0.9 times combined length of propodus and dactylus; propodus 0.3 times carpus, with deep notch on distal corner, for entire length of article; dactylus slightly swollen distally, with 13 stiff setae projecting radially. Pereopod 3and 4 ( Fig. 35 J, K) basis lengths 1.9, 1.4 times distal articles together, respectively. Pereopod 5 ( Fig. 35 L) very short, 0.5 times as long as 4th pereopod; basis 1.0 times distal articles together.

Uropod ( Fig. 35 M) peduncle 1.4 times as long as pleonite 6, 0.90 times exopod, 0.73 times endopod, with 3 spiniform setae on inner margin. Exopod length 1.09 times 1st article of endopod, with 9 plumose or simple setae on inner margin and apical end, and with 3 simple setae on dorsal surface. Endopod 1st article 3.1 times 2nd article, with 7 spiniform setae on inner margin and 3 plumose setae on outer margin; 2nd article with 4 spiniform setae on inner margin; terminal robust setae well defined at base.

Etymology. The species name refers to the Sulu Sea where the specimen was collected.

Remarks. Eudorella suluensis sp. nov., E. hwanghaensis , E. bathyhwanghaensis , and E. ryukyuensis are distinguished from the other members of the genus in their combination of the following characters. (1) The frontal margin of the carapace is markedly serrated. (2) The lower end of the antennal notch slightly behind the frontal margin of carapace. (3) The antenna 1 peduncle 3rd article is subequal in length to the 2nd. (4) The antenna 2 has one or a few setae on the basal margin. (5) The basis of maxilliped 2 has a few setae on the inner margin and dorsal surface, and is shorter than the combined length of the ischium, merus and carpus. (6) The basis of pereopod 1 has two robust spiniform setae on the ventral surface. Eudorella suluensis is distinguished from the other three species mentioned above by the combination of the following characters. (1) The upper front corner of the carapace bears a few tubercles. (2) The opening of the siphon is directed somewhat forward, and the frontal margin of carapace slants forward. The presence of tubercles on the upper front corner of carapace is unique in the genus.

Distribution. Western region of the Sulu Sea, The Philippines, 688– 693 m.

Figures

FIGURE 3. Eudorella acuticaudata sp. nov., adult male. A, body, lateral view; B, anterior portion of body, dorsal view; C. anterior portion of carapace; D, antenna 1; E, antenna 2; F, maxilliped 3; G – K, pereopods 1 – 5; L, pleopod 1; M, uropod with pleonite 6.

FIGURE 35. Eudorella suluensis sp. nov., subadult male. A, body, lateral view; B, anterior portion of body, from above; C, carapace; D, antenna 1; E, antenna 2; F, maxilliped 2; G, maxilliped 3; H – L, pereopods 1 – 5; M, uropod with pleonite 6.