Eudorella parahirsuta Akiyama & Gamô, 2012, sp. nov.

• Main Authors: Akiyama, Tadashi, Gamô, Sigeo
• Format: Text
• Language: unknown
• Published: Zenodo 2012
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Cumacea; Leuconidae; Eudorella; Eudorella parahirsuta; Pacific; Seta; Northeast Atlantic
• Online Access: https://dx.doi.org/10.5281/zenodo.6178476; https://zenodo.org/record/6178476

Eudorella parahirsuta sp. nov. (Figs. 32, 33) Material examined. Holotype, ovigerous female, 5.3 mm, dissected (NSMT-Cr 22159), off Chiba, 34 ° 42.35 ˏN, 140 ° 45.82 ˏE – 34 ° 41.22 ˏN, 140 ° 44.60 ˏE, 2234–2240 m (KT-01- 8, St. TK- 4), 23 June 2001. Paratypes; 2 preparatory female, 5.2, 5.4 mm, dissected (NSMT-Cr 22160), KT-01- 8, St. TK- 4; 1 subadult male, 4.6 mm, dissected (NSMT-Cr 22161), Okinawa Trough, 28 ° 46.17 ˏN, 127 ° 19.10 ˏE – 28 ° 46.95 ˏN, 127 ° 19.68 ˏE, 974–997m (KT-04- 24, St. F 2), 22 October, 2004; 1 subadult male, 4.8 mm (NSMT-Cr 22162), Okinawa Trough, 28 ° 57.07 ˏN, 127 ° 46.51 ˏE – 28 ° 57.88 ˏN, 127 ° 47.11 ˏE, 1094–1105 m, (KT-04- 24, St. F 3) 22 October, 2004; 1 ovigerous female (badly damaged), 1 preparatory female, 5.3 mm, dissected (NSMT-Cr 22163), off Shimokita, 41 °04.5ˏN, 143 °52.0ˏE – 41 °04.5ˏN, 143 °52.0ˏE, 3000m (KT 08- 27, St. B 16), 25 October, 2008. Description. 2 ovigerous females (1 specimen badly damaged) and 3 preparatory females, 5.2–5.4 mm in length (Fig. 32). Body slender, integument weakly calcified, covered with fine setae (Fig. 32 A). Carapace length about 0.20–0.21 times total body length, 1.4–1.5 times greatest width, and 1.4–1.7 times the depth; upper front corner vaulted, with bundle of long setae; frontal margin serrated, not reaching near siphon; antennal notch with 1–3 teeth on lower end; anterolateral corner round; inferior margin curved, weakly serrated. Pereon 1.1 times carapace. Pleon 0.55–0.56 times total body length; dorso-posterior end of 5 th pleonite without long setae. Antenna 1 (Fig. 32 D) 1 st article of peduncle with 2–4 plumose setae on lower margin and 5–6 plumose or simple setae on inner margin; 3 rd article of peduncle shorter than 2 nd, with 4–5 plumose and 1 simple seta on outer margin, with 5–7 plumose setae on inner margin and with 1–2 simple setae on frontal margin; main flagellum shorter than or subequal to 2 nd article of peduncle, with 3–5 simple setae on outer margin; accessory flagellum shorter than 1 st article of main flagellum. Antenna 2 with no setae on lower margin (Fig. 3 E). Right and left mandibles, maxilla 1 and maxilla 2 normal (Fig. 32 F–H). Maxilliped 1 (Fig. 32 I) with 3–5 small branchial lobules. Maxilliped 2 (Fig. 32 J) basis shorter than combined length of succeeding 3 articles, with 1 seta on inner margin (arrowhead). Maxilliped 3 (Fig. 32 K) basis length 0.9 –1.0 times length of distal articles together, with 6–10 plumose setae on inner margin and 3–5 setae on ventral surface; ischium with a spine on inner margin; carpus with 9– 12 plumose setae on inner margin. Pereopod 1 (Fig. 32 L) basis length 0.6 times distal articles together, with several simple setae on outer margin; propodus 1.3 times carpus and 1.9–2.1 times dactylus. Pereopod 2 (Fig. 32 M) basis length 0.6–0.7 times distal articles together; carpus extremely elongate, 1.9–2.1 times merus and 1.8–1.9 times combined length of propodus and dactylus; propodus short, with shallow notch on distal corner; dactylus not swollen, with 10–11 stiff setae. Pereopod 3 (Fig. 32 N) basis length 1.8–2.1 times remaining distal articles. Pereopod 4 (Fig. 32 O) basis length 1.5–1.9 times distal articles together. Pereopod 5 (Fig. 32 P) basis length 1.1–1.6 times distal articles together. Uropod (Fig. 32 Q) peduncle length 1.3 times length of pleonite 6, 0.96–1.06 times exopod and 1.14–1.25 times 1 st article of endopod, with 4–6 spiniform setae on inner margin. Exopod 1.14–1.19 times 1 st article of endopod, with 7–9 plumose or simple setae on inner margin and apical end, 3–5 simple setae on dorsal surface, and 3–5 simple setae on ventral surface. Endopod 1 st article 3.1–3.7 times 2 nd, with 7–8 spiniform setae on inner margin and 3–4 short simple setae on outer margin; 2 nd article with 2–3 spiniform setae on inner margin; terminal seta longer than 2 nd article, defined at base. Subadult male, 4.6 mm in length (Fig. 33). Carapace 0.22 times as long as total body length, 1.5 times the greatest width and 1.5 times depth; upper front corner with a bundle of setae projecting forward and upward; frontal margin prominently serrated; antennal notch absent; inferior margin with 9, 14 teeth. Pereon length 1.0 times carapace length. Pleon length 0.57 times total body length, with 2 pairs of undeveloped pleopods; dorso-posterior end of 5 th pleonite with no long setae. Antenna 1 (Fig. 33 D) 1 st article of peduncle with 3 and 4 plumose setae on lower and inner margin respectively; 3 rd article of peduncle shorter than 2 nd, with 4 plumose setae and 1 simple seta on outer margin, with 6 plumose setae on inner margin, and 2 simple setae on frontal margin. Main flagellum subequal to 2 nd article of peduncle, with 4 simple setae on outer margin of 1 st article. Accessory flagellum slightly shorter than 1 st article of main flagellum. Antenna 2 (Fig. 33 E) with elongate flagellum; peduncle with 3 plumose setae. Maxilliped 3 (Fig. 33 F), basis 1.0 times distal articles, with 8 and 5 plumose setae on inner margin and ventral surface, respectively; ischium with 1 spine on inner margin. Pereopod 1 (Fig. 33 G) basis length 0.65 times length of distal articles combined; propodus 1.4 times merus and 1.9 times dactylus. Pereopod 2 (Fig. 33 H) basis length 0.9 times distal articles combined; carpus 2.1 times merus and 1.6 times combined length of propodus and dactylus; dactylus with 10 stiff setae projecting radially. Pereopod 3 and 4 (Fig. 33 I, J) basis lengths 2.6, 2.2 times distal articles together, respectively, broad at base. Pereopod 5 (Fig. 33 K) basis length 1.5 times distal articles combined. Undeveloped pleopod (Fig. 33 L) normal. Uropod (Fig. 33 M) peduncle length 1.4 times pleonite 6, 0.97 times exopod, and 1.13 times 1 st article of endopod, with 5 spiniform setae on inner margin. Exopod length 1.17 times the 1 st article of endopod, with 8 plumose or simple setae on inner margin and apical end, 4 simple setae on dorsal surface, and 4 or 5 simple setae on ventral surface. Length of 1 st article of endopod 3.3 times length of 2 nd, with 9 spiniform setae on inner margin and 3 simple setae on outer margin; 2 nd article with 3 minute spiniform setae on inner margin; robust terminal setae longer than 2 nd article, defined at base. Etymology. This species name refers to the similarity in morphology with E. hirsuta Sars, 1869. Remarks. Females of E. parahirsuta sp. nov. are closely similar to E. hirsuta Sars, 1869, found in the Northeast Atlantic, 207–2524 m, especially in the shape of the carapace and pereopod 2 with an extremely elongate carpus. However, they can be distinguished as follows. (1) The serrated frontal margin of the carapace does not reach near the siphon (reaching near the siphon in E. hirsuta ), (2) The propodus of pereopod 1 is much longer than the carpus (subequal in length in E. hirsuta ) and twice as long the dactylus (only about 1.5 times in E. hirsuta ). In the subadult male, the frontal margin of the carapace in E. parahirsuta is markedly serrated (not serrated in E. hirsuta ). Distribution. Pacific coast of northern Honshu, off Boso Peninsula, and Okinawa Trough, 974–3000 m. : Published as part of 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, pp. 1-56 in Zootaxa 3319 on pages 46-49, DOI: 10.5281/zenodo.213431