Systematic study on Hydrozoans (Phylum Cnidaria) form Nansei Islands

1992-1994年对南西群岛的水螅纲（PhylumCnidaria）进行了系统研究。通过对7个岛屿（奄美大岛、冲绳、赤贺岛、宫古岛、石垣岛、黑岛、西表岛）36个站位的资料收集和野外调查，鉴定出水螅水母7目39属47种，水螅虫2目21属27种。加上已报道的冲绳沿岸的水螅虫2目25属30种，南西诸岛共7目67属82种，显示了该海域水螅虫区系的丰富性。本次研究所获水螅水母类均为本区首次记录。其中13种为日本新记录或未鉴定种，并对其中大部分水母类的生长、胞体、配子和幼虫进行了研究。此外，个体变异范围和地理数据与以前的记录一起汇编。在南西诸岛采集到的水螅虫大多数也分布在从九州到北海道的任何特定地区，目前水螅水母有11种，水螅虫有4种仅分布在南西诸岛。南西群岛的水螅水母类区系与我国水螅水母类分类研究较好的台湾海峡和厦门附近的水螅水母类区系相似。

The systematic study of the Class Hydrozoa (PhylumCnidaria) in the Nansei Islands has been conducted during 1992-1994. The collection of materials and field work was done at 36 stations on seven islands (Amami-oshima, Okinawa Island, Aka Island, Miyako Island, Ishigaki Island, Kuroshima Island, Iriomote Island) and through laboratory-rearing hydromedusae of 47 species of 39 genera (7 orders) and hydropolyps of 27 species of 21 genera (2 orders) were recognized. Together with hydropolyps of 30 species of 25 genera (2 orders) which were already reported from mainly shores of Okinawa Island, a total of 82 species of 67 genera (seven orders) are distributed in Nansei Islands, showing a rich hydrozoan fauna in this study area. All hydromedusae collected in the present study are the first record in this area. Among them, 13 species are new to Japan or unidentified, and the growth, cnidome, gametes, and larva of most of these medusan species were clarified. Further, range of individual variation and biogeographical data were compiled together with former records. Most of the hydrozoans collected in the Nansei Islands are also distributed in any given area from kyushu to Hokkaido, and at present hydromedusae of 11 species and hydropolyps of 4 species are exclusively distributed in the Nansei Islands. It is known that hydromedusa fauna in the Nansei Islands are similar to that of Taiwan Strait and around Amoy, China where the taxonomic study of hydromedusae were well studied.