蜾蠃蜚属(甲壳动物:端足目)的一新种

A NEW SPECIES OF GENUS COROPHIUM (CRUSTACEA:AMPHIPODA)

在中国对虾养殖饵料生物调查中,中国科学院海洋研究所郑严先生于1983年在山东荣城县黄山养虾场等地的潮间带泥滩中,发现了大量的管栖甲壳动物端足目蜾蠃蜚属Corophium。当地渔民将其同底泥一起挖取,投入养虾池,实践证明它们是一种养殖对虾的优质活饵料,其标本经整理鉴定为一新种。

Corophium denticulatum sp. nov.(Fig. 1-2)Holotype: 1994-C-A-001, Mature male, 8.2mm in length, Huangshan Shrimp Farm, Rongcheng County, Shandong Province. 1983, IV, 28. Collected by Zheng Yan. Paratype: 1994-C-A-002. 8♂♂, large specimens, body 7.4mm; 8♀♀, large specimen, 8.0mm in body length. Locality and collecting date as holotype. Other material examined: About 800 specimens, same as holotype.Body strong, head wider than long. Rostrum and lateral lobes acutely rounded; eyes absent.1-3 pereonites short and wide, 4-7 pereonites longer. Posterodistal angle of pleonites 1 and 2 acutely rounded; pleonite 3 longer than others, postero-lateral angle bluntly rounded; pleonites 4-6 well defined; pleonites 5 and 6 short and wide. Telson triangular, distal end with small notch, dorsal surface with medial furrow, lateral ribs with 1-2 small setae, lateral angle rounded.Male: Antenna 1 slender and short; peduncle subequal to flagellum. Article 1 of peduncle strong and long, inner margin without tooth; ventral margin with a terminal spine and a row of setae. Second article of peduncle slender and short, 3/5 as long as article 1; third article of peduncle shortest, 1/2 as long as article 2, both with setae. Flagellum with 14-18 articles. Antenna 2 thick and long, distal end of basal article of peduncle with two teeth, inner one longer and stronger, curved upward. Antipenultimate article of peduncle longer than wide, distal end of inner border with a lobe-like projection; penultimate article about 2.5 times as long as antipenultimate article, distal end of inner lower edge with a strong tooth; inner lower margin with a row of 6-9 teeth; ultimate article of peduncle slender, su-bequal to penultimete article in length, inner lateral border with 5-6 teeth and setae-group. Flagellum shorter than ultimate article of peduncle, with two distinct articles, inner lateral side of basal article with 4-5 teeth.Head and antenna 1 of female similar to those of male. Flagellum of antenna 1 with 12-15 articles. Antenna 2 slender and small; antipenultimate article of peduncle with a strong tooth on ventral distal end; middle of inner margin with a movable spine.Molar of mandible developed, palp with 2 articles; distal end of article 1 with long seta; article 2 slender, longer than article 1, distal end with a long plumose seta. Lower lip with inner lobe, lateral angle projected. Inner plate of maxilla 1 small, distal end with a seta, palp of outer plate with 2 articles, article 2 long. Maxilla II with 2 lobes, frontal margin of inner lobe with a row of plumose setae. Palp of maxilliped with 4 articles.Coxal plate of gnathopod 1 produced forwardly; distal end with 3 plumose setae, frontal margin with 5 short setae. Carpus twice as long as wide, palmar margin with a row of spines; dactylus clawshaped. Gnathopod 2 larger than gnathopod 1, frontal margin of basis straight; dactylus sickle-shaped, without attaching teeth. Basis of pereopods 1 and 2 long, dactylus claw-shaped; distal angles of merus and propodus with spines on pereopods 3 and 4. Pereopod 5 longest, basis narrow and long.Uropods 1 and 2 strong. Uropod 3 short and small; peduncle as long as wide; ramus short and small, with long setae.This new species differs from other species of Corophium whose pleonites 4-6 are well defined in the inner margins of ultimate and penultimate peduncular articles of antenna 2, and in the fragellum articles in the males being armed with a row of teeth.The present species is closely allied to Corophium volutator japonica Hirayama in many aspects, but the latter without a row of teeth on peduncle of antenna 2.This new species is a tube dweller inhabiting mud-flats in the intertidal zone. Shrimp farmers often digged and transplanted them with bottom sediment into shrimp ponds to feed cultured shrimps.