Eualus leptognathus (Stimpson, 1860)

Xu, Peng & Li, Xin-Zheng, 2015, Report on the Hippolytidae Bate (sensu lato) from China seas, Zoological Systematics 40 (2), pp. 107-165 : 142-143

Eualus leptognathus (Stimpson, 1860) ( Fig. 22 )

Hippolyte leptognatha Stimpson, 1860: 103 . Type locality: Hokkaido.

Spirontocaris japonica Yokoya, 1930: 273 , 533.

Spirontocaris leptognatha Yokoya, 1933: 26 .

Eualus leptognathus Holthuis, 1947: 11 , 43; Miyake & Hayashi, 1967: 258, fig. 5.

Material examined. MBM109912 , 1 ♂ (cl 2.34 mm), Shandong, Yantai, Kongtong Island , 1933-12-13 ; MBM109913 , 1 ovig. ♀ (cl 4.27 mm), Shandong, Qingdao, Zhonggang , 1955-2-27 ; MBM109915 , 3 ovig. ♀ (cl 4.04–4.33 mm), 2 ♂ (cl 3.22, 3.56 mm), Shandong, Qingdao, Guizhou Road , 1955-3-19 ; MBM109916 , 2 ♀ (cl 3.76, 4.19 mm), 3 ♂ (cl 3.71–4.05 mm), Shandong, Qingdao, Zhonggang , 1956-2-4, coll. Feng-Xuan Zhang ; MBM109917 , 3 ♂ (cl 2.15–3.01 mm), Shandong, Qingdao, Fish Farm , 1955-11-18, coll. Feng-Xuan Zhang ; MBM129738 , 1 ovig. ♀ (cl 3.94 mm), 5 ♀ (cl 4.07–4.35 mm), 3 ♂ (cl 3.43–3.62 mm), Shandong, Qingdao, Guizhou Road , 1955-3-19 ; MBM109921 , juvenile (cl

© Zoological Systematics, 40 (2): 107–165 0.76–0.91 mm), Shandong, Qingdao, Yumingzhui , 1955-9-20 ; MBM109922 , 2 ♂ (cl 3.37, 3.92 mm), Shandong, Yantai Port, Zhifu , 1954-5-18 ; MBM109923 , 1 ♀ (cl 3.92 mm), juvenile (cl 0.63–1.16 mm), Shandong, Qingdao, Zhonggang , 1955-7-14 .

Description. Rostrum longer than carapace, laterally compressed, apically upward; dorsal margin with 3–6 teeth on proximal half, and distal half of ventral margin armed with 2–5 teeth in front of foremost tooth on dorsal margin. Antennal spines acutely pointed, setting below obtuse suborbital angle and pterygostomian spine small but distinct.

Pleura of fourth somite unarmed posteriorly but that of fifth with small posteroventral tooth. Telson about 1.3 times as long as sixth abdominal somite, with 4 or 5 pairs of dorsal spines; posteriormargin of telson terminates in small acute tooth with 2 pairs of spines and one mesial pair of stiff setulose setae.

Eye rather large; stalk longer than cornea.

Stylocerite is sharp, reaching distal margin of antennular peduncle; 3 segments of antennular peduncle each with distinct spiniform distal tooth. Antennal scale broad, 5 times as long as wide, slightly overreaching apex of rostrum; lateral margin straight, distolateral tooth falling short of rounded distal margin of blade. Third maxilliped with exopod and epipod, reaching distal margin of antennal scale.

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

First pereopod stout and short, reaching distal margin of antennular peduncle. Second pereopod slender, reaching or overreaching distal margin of antennal scale. Biunguiculate dactylus of third pereopodarmed with 6 or 7 accessory spines along entire length of flexor margin; merus with 4–7 prominent lateral spines distally. Merus of fourth pereopod with 4 or 5 lateral spines distally; fifth pereopod reaching distal tip of stylocerite, merus with 3 or 4 distolateral spines.

Appendix interna of female expanded in distal part bearing many coupling hooks; appendix masculine of male large and short, being 1/3 length of appendix interna with truncated tip bearing eleven long hairs.

Coloration in life. Body generally translucent with some small brown spots; eggs are brown green.

Distribution. Northern China seas; Sea of Japan; shallow water or clear seaweed pond, like attaching to objects.

Figures

Fig. 22. Eualus leptognathus (Stimpson, 1860), carapace, lateral view. Scale bar=1 mm.