放逸短沟蜷的生态研究(英文)

STUDIES ON ECOLOGICAL CHARACTERISTICS OF SEMISULCOSPIRA DECIPIENS

1 994年至 1 996年作者在日本木崎湖 ,对放逸短沟蜷的分布、生长、卵及水温进行了一系列的调查和实验研究 .结果表明此贝生活于沙地 ,一年中都产卵 ,并在水温 1 7～ 2 1℃时有二次产卵高峰 ,随着水温的升高 ,产卵加快 .成体雌性一年中体内都含有胚胎 ,当胚胎壳发育到 2 .5～ 4个螺层时新生贝由母体产出 ,而且春季和秋季产出较多 .

For this paper author studied on the distribution of S.decipiens,and the rslationship between its growth,spawn and water temperature by a series of ynvestigation and experiments in the Kazaki lake of Japan from March of 1994 to Feburary of 1996.The research results show that there are more S.decipiens individuls in the sandy habitat.usually S.decipiens spawnes at any time in a year,and there are two spawning peak periods (from April to June ,from September to Octaber)with an appronimate water temperature of 17-21 ℃.S.decipiens has a rapid spawn or reproduction with an increase of water temperatute,even at a high water temperature(25-28 ℃).There are some embryo shells in the body of female S.decipiens all the time in a year.The newborn have developed when the embryo shells in the body of female S.decipiens is more and more in spring and autumn.