摘要
本文观察研究淡水单孔蚓Monopylephorus limosus繁殖和发育。成虫采自舟山本岛,体长30-80 mm,体节数86-145。精巢位于第Ⅸ节,卵巢位于第Ⅹ节。精漏斗大,输精管膨管状。雄性导管和受精囊成对。雄孔开口于第Ⅺ节,受精囊孔位于Ⅸ/Ⅹ节。无阴茎鞘。成熟个体环带不明显。茧呈各种形状,通常为椭圆形,长径1.25-5 mm、短径0.7-2 mm,内含0-59个卵。单孔蚓的早期胚胎发育和某些多毛类很相似,卵裂为螺旋型卵裂。外包和内陷法形成原肠。培养水温在17-19℃时,约经20天幼蚓就破茧而出,孵化率为80%。幼蚓经90天可成为成体,成活率为90%。110天左右产卵,繁殖期为4-10月。繁殖适温为16-23℃。一年可繁殖2代,多至3代。
This report deals with the reproduction and ontogenesis of Monbpylepholus limosus according to our experimental research. The adults were collected from the main island of Zhoushan. Their body lengths were within 30-80 mm, and the segments number 86-145. The testes were in segment IX and the ovaries in X. Having large sperm funnels with vasa deferentia of artia,the male ducts and the spemathecae were in pairs respectively. The male pore was in XI, and the spermathecal pore in IX/X. The clitellum of the mature individual was not clear.The cocoons were variable in shape, usually being ellipsoids with long axis 1.25-5 mm and short axis 0.7-2mm, each containing 0-59 eggs.This worm is similar to several Polychaetes in early development of the embryo with spiral cleavage and gastrulation by epiboly and inmagination.The larvae could be incubated with a incubation rate of 80% under a water temperature of 17-19℃ for about 20 days.The larvae grow to maturity in 90 days with a survival rate of 90,%and start to spawn after 110 days. Reproduction during a year can be 2-3 generations, reproduction season being April to October, and optimum reproduction temperature 16-23℃.
