台湾海峡十盘水母属二新种记述(软水母亚纲,锥螅水母目)

根据2007年5月在台湾海峡(20.849°～27.056°N,114.920°～121.241°E)水域采集的标本分析结果,发现了软水母亚纲二新种,即粗手十盘水母,新种(Staurodiscus crassonema sp.nov.)和宽球十盘水母,新种(Staurodiscus latibulbussp.nov.).现将新种形态特征描述如下,为今后编写水螅水母动物志及海洋调查提供参考.

Two New Species of Genus Staurodiscus from the Taiwan Strait,China(Leptomedusae,Conica,Hebellidae)

Samples of Staurodiscus were collected from the Taiwan Strait at 20.849°～27.056°N,114.920°～121.241°E,during May 2007.Two new species of Staurodiscus i.e.Staurodiscus crassonema sp. nov. and Staurodiscus latibulbus sp. nov. are described.All type specimens are deposited in the Third Institute of Oceanography,SOA.Staurodiscus crassonema sp. nov. (Fig.1)At present time,only 14 valid species in the Staurodiscus Haeckel,1879 are known.This new species differs from other species of Staurodiscus in having 4 primary radial canals,each lateral branches of radial canals no joining ring canal,and manubrium without gastric pouches,but the new species is closed to Staurodiscus heterosceles Haeckel,1879,S. tetrastaura Haeckel,1879 and S. gotoi(Uchida, 1927).The former differs from the latter three species by: 1)radial canals with 2 pair of lateral branches,opposite each other,not reaching ring canal, 2)four thick and stiff,hollow tentacles with elongated conical bases and with black pigment scattered whole length of tentacle, 3)10 well developed cordyli,club-shaped,and 12 small cordyli,large and small ones not regularly alternating (Tab.1).Holotype(TS040),Taiwan Strait ZD-XM616 station(23.575°N,119.009°E),depth 59 m,4 May 2007,Xiang Peng(SOA);and paratype(TS041～043),Taiwan Strait ZD-XM617 station(23.462°N,119.003°E),depth 54 m,4 May 2007,Xiang Peng(SOA).Etymology.Crassonema,Latin,means crass nema.The species name refers to the tentacles thick and stiff with elongated conical bases.Staurodiscus latibulbus sp. nov. (Fig. 2)This new species can be easily distinguished from other members of Staurodiscus by the manubrium with gastric pouches,but this new species is closed to Staurodiscus quadristoma Bouillon,1984,which differs from them by: 1)manubrium with 12 gastric pouches,nearly short conical,of which 4 perradial and 8 adradial, 2)subumbrella with 12 radial canals arise from terminal gastric pouches,of which 4 perradial canals joining ring canal,each with 1～2 opposite blind lateral branches,and 8 adradial blind radial canal, 3)8 marginal tentacles,4 perradial and 4 interradial,both lateral extension of all tentacle bulbs,elliptical-shaped(Tab.1).Holotype(TS044),Taiwan Strait ZD-XM616 station(23.575°N,119.009°E),depth 59 m,4 May 2007,Xiang Peng(SOA).Etymology.Latibulbus,Latin,means lati-bulb.The species name refers to the both lateral extension of tentacle bulbs.