Eudorella fusafusa, 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 : 31

Eudorella fusafusa sp. nov.

( Figs. 20–22 )

Material examined. Holotype, ovigerous female, length 6.2 mm (NSMT-Cr 22132), southwest of Hokkaido, 42°02.80ˏN, 141°18.77ˏE – 42°02.35ˏN, 141°18.94ˏE, 295 m (KT-05-6, St. BT-1), 6 April, 2005. Paratypes; 6 young males, length 4.3–4.7 mm (NSMT-Cr 22133), same date and locality as holotype female.

Description. Holotype ovigerous female ( Figs. 20 , 21 ). Body weakly calcified, covered with numerous hairs. Carapace ( Fig. 20 C) length 0.16 times total body length, as long as greatest width, latter being slightly longer than depth; upper front corner with a bundle of long setae projecting upward; a row of 4 or 5 long setae present on each side of carapace behind pseudorostral lobe; antennal notch with 4 and 3 teeth on upper and lower end, respectively; anterolateral angle with prominent tooth directed slightly upward, succeeded by a series of 12 teeth on inferior margin. Pereon 1.8 times as long as carapace. Pleon rather thick, 0.55 times total body length. Dorso-posterior end of pleonite 5 with many small setae.

Antenna 1 ( Fig. 20 D) 1st article of peduncle with 3 and 5 setae on lower and inner margin, respectively; 3rd article of peduncle slightly shorter than 2nd, with 5 plumose setae and 1 simple seta on outer margin, 5 plumose setae on inner margin. Basal article of main flagellum with 3 simple setae on outer margin. Accessory flagellum as long as basal article of main flagellum. Antenna 2 ( Fig. 20 E) with 3 plumose setae on outer margin, no setae on lower margin. Mandibles, maxilla 1 and maxilla 2 normal ( Fig. 20 F–H). Maxilliped 1 ( Fig. 20 I) with 8 well developed branchial lobules. Maxilliped 2 ( Fig. 20 J), basis short, as long as combined length of succeeding 3 articles, with no spine or setae on inner margin. Maxilliped 3 ( Fig. 20 K) basis length 1.2 times distal articles together, with 9–10 and 5–6 plumose setae on inner margin and ventral surface, respectively; ischium with a prominent spine on inner margin; carpus with 7 plumose setae on inner margin.

Pereopod 1 ( Fig. 21 A) basis length 0.7 times distal articles together, with several plumose setae on middle portion of ventral surface, along with 2 plumose setae on inner and outer surface; propodus 1.5 times as long as carpus and 2.2 times dactylus. Pereopod 2 ( Fig. 21 B) basis length 0.8 times length of distal articles combined, with a row of plumose setae on inner margin and a row of simple setae on outer margin; merus with 6 and 4 simple setae on inner and outer margins, respectively; carpus as long as merus and much shorter than combined length of propodus and dactylus; propodus with deep notch on distal corner for nearly entire length of article; dactylus swollen distally, with 11 stiff setae on lateral margin and apical end. Pereopod 3 ( Fig. 21 C) basis length 1.7 times length of distal articles together, with 13 plumose setae on inner margin and 5 simple setae on outer margin; carpus with 4 simple setae. Pereopods 4 and 5 ( Fig. 21 D, E) bases 1.5 and 1.1 times distal articles together, respectively.

Uropod ( Fig. 21 F) peduncle 1.5 times as long as pleonite 6, 1.10 times exopod, 0.92 times endopod, with 10 short stiff setae on inner margin and with small setae on dorsal surface and outer margin. Exopod 1.02 times 1st article of endopod, with 10 setae on inner margin and many simple setae on outer margin. Endopod 1st article 4.3 times 2nd, with 9 or 10 spiniform setae on inner margin and with 7 simple setae on outer margin; 2nd article with 3 spiniform setae on inner margin and with a simple seta on outer margin; terminal setae defined at base.

Young male ( Fig. 22 ). Body furnished with numerous short setae. Carapace length 0.20 times total animal length, 1.2 times as long as greatest width, latter being subequal to depth; upper front corner with numerous long setae directed upward ( Fig. 22 C); a row of 4–5 simple setae present on each side of carapace, behind pseudorostral lobe; antennal notch very shallow, with 6 and 4 teeth on upper and lower end, respectively; anterolateral angle with prominent tooth directing forward, succeeded by a series of teeth on inferior margin. Pereon 1.2 times carapace. Pleon 0.6 times total body length. pereopods with numerous setae, like holotype female. Pleopod small, with minute ramus ( Fig. 22 D).

Etymology. The species name is derived from a Japanese word which means hairy, referring to the very setiferous body.

Remarks. The present new species is closely related to Japanese specimens of Eudorella orientalis sp. nov., E. setoensis Akiyama & Gamô, 2006 , E. breviflagella sp. nov., and E. bathyalis Vassilenko & Tzareva, 2004 , in having a low of several setae on each side of the carapace, but is distinguished from the latter four species by the combination of: (1) numerous setae on the body, including setae on the outer margin of the basis of pereopods 2 and 3; (2) its short carapace, 0.16 times body length,; (3) the upper end of antennal notch bearing four teeth; and (4) the short 2nd article of the uropod endopod, one fourth of the 1st article. Eudorella fusafusa is also similar to E. truncatula ( Bate, 1856) , but distinguished from the latter by: (1) a row of setae on each side of the carapace (no seta in E. truncatula ); (2) trunk and appendages bearing numerous setae (not so setiferous in E. truncatula ); and (3) the uropod endopod 1st article being 4 times as long as the 2nd article (3 times or less in E. truncatula ). Distribution. Pacific coast of northern Japan, 295m.

Figures

FIGURE 20. Eudorella fusafusa sp. nov., ovigerous female. A, body, lateral view; B, anterior portion of body, from above; C, carapace; D, antenna 1; E, antenna 2; F, mandibles; G, maxilla 1; H, maxilla 2; I – K, maxillipeds 1 – 3.

FIGURE 21. Eudorella fusafusa sp. nov., ovigerous female. A – E, pereopods 1 – 5; F, uropod with pleonite 6.

FIGURE 22. Eudorella fusafusa sp. nov., young male. A, lateral view; B, anterior portion of body, from above; C, carapace; D, pleopod 1.