Eualus kikuchii Miyake & Hayashi, 1967

Xu, Peng & Li, Xin-Zheng, 2015, Report on the Hippolytidae Bate (sensu lato) from China seas, Zoological Systematics 40 (2), pp. 107-165 : 142

Eualus kikuchii Miyake & Hayashi, 1967 ( Fig. 21 )

Eualus kikuchii Miyake & Hayashi, 1967: 261 , figs 6–7; Hayashi & Miyake, 1968: 129, fig. 4; Noël, 1978: 32 (key); Chace, 1997: 43 (list); Komai & Fujiwara, 2012: 74, figs. 6–8. Type locality: Tomioka Bay, Amakusa Island.

Eualus bulychevae Miyake, 1982: 184 (part; list); Komai & Hayashi, 2002: 390 (list).

Material examined. MBM109926 , 2 ♀ (cl 1.31–2.67 mm), 2 ovig. ♀ (cl 1.87–2.43 mm), 1958-10-23, st. 1098, 55m, no . V64 B-5 ; MBM109931 , 6 ♂ (cl 1.26–1.94 mm), 3 ♀ (cl 1.50–2.39 mm), 8 ovig. ♀ (cl 1.67–3.19 mm), 1957-7-12, st. P401, 52 m, sandy mud, BT, no. VII1B-34, coll. Rui-Yu Liu ; MBM109932 , 4 ovig. ♀ (cl 3.05–3.43 mm), Yellow Sea, 1958-4-9, st. PY207, 45 m, mud with shell fragment, BT, no. VXIV63B-10 .

Description. Rostrum about half length of carapace, nearly straight, slightly descending, reaching or slightly falling short of basal segment of antennular peduncle; dorsal margin with 4–6 teeth, posteriormost one on carapace slightly posterior to margin of orbit; ventral margin unarmed or armed with only one subterminal tooth. Carapace with antennal tooth moderately strong; pterygostomial tooth present or not in males.

Pleurae of fourth and fifth abdominal somites each with smallposteroventral tooth. Sixth somite 1.6 times as long as fifth mid-dorsal length. Telson about 1.4 times longer than sixth abdominal somite; dorsal surface with four or five pairs of dorsolateral spines; posterior margin with two pairs of spines and one mesial pair of stiff setulose setae.

Eye subpyriform; cornea with distinct ocellar spot. Antennular peduncle reaching distal 0.4 of antennal scale. Basal segment with strong distolateral tooth reaching nearly to midlength of antennal scale; distal two segments combined much shorter than basal segment, each with distinct spiniform distal tooth. Sharp stylocerite reaching distal margin of basal segment. Antennal scale about 4/5 length of carapace, 2.6 times as long as wide; lateral margin nearly straight, with distolateral tooth reaching rounded distal margin of blade.

Mandible with two-segmented palp, slender incisor process and stout molar process. Third maxilliped moderately long and slender, overreaching antennal scale by 1/3 length of ultimate segment; ultimate segment with 6–8 corneous spines distally; exopod exceeds middle of antepenultimate segment; epipod present.

First to third pereopods with strap-like, terminally hooked epipods.

First pereopod reaching nearly midlength of antennal scale. Chela about 1.5 times longer than carpus; dactylus about 0. 6 times longer than palm; merus about 1. 7 times longer than carpus. Second pereopod overreaching antennal scale by chela and half of carpus; carpus with seven sub-segments.

Third to fifth pereopods with similar structure.

Third pereopod overreaching antennal scale by length of dactylus and 2/5 of capus; dactylus less than 1/3 times as long as propodus, armed with 4–6 accessory spines along entire length of flexor margin (excluding terminal claw); propodus with row of spinules on flexor margin; carpus about half length of propodus; merus with 2–4 prominent lateral spines distally. Merus of fourth pereopod with 1–3 lateral spines distally; merus of fifth pereopod unarmed or with only one distolateral spine.

In males, endopod of first pleopod with appendix interna elongate subtriangular; endopod of second pleopod with appendix masculina slightly shorter than appendix interna.

Coloration in life. Body and appendages generally translucent.

Distribution. Yellow Sea; Pacific side of mainland Japan, from Sagami Sea to Amakusa, Kyushu, 40– 230 m.

Remarks. This species was not previously recorded from the China seas.

Figures

Fig. 21. Eualus kikuchii Miyake & Hayashi, 1967. A. Carapace, lateral view; B. Abdominal pleurae, lateral view; C. Antennular peduncle, dorsal view; D. Antennal scale, dorsal view; E. Telson, dorsal view; F. Third maxilliped,lateral view; G. First pereopod, lateral view; H. Second pereopod, lateral view; I. Third pereopod, lateral view; J. Endopod of second pleopod, ventralview (setae partially omitted). Scale bars=1mm.