斜口涡虫(原卵黄目,斜口科)的生物学特性

摘要：本文报道了采自广东惠州市东江支流(23°09′00. 31"N，114°22′26.59″E)的中国涡虫一新纪录目原卵黄目(Prolecithophora)斜口涡虫(Plagiostomum sp.)。该虫体长4.51 ～6.00 mm，体被不规则的褐色细网纹，头钝圆，尾圆锥形，体中部圆柱状，眼点4只。该涡虫运动...

Biological Characteristics of Plagiostomum sp. (Prolecithophora,Plagiostomidae)

This study for the first time reported a newly recorded order of turbellarians in China.Prolecithophora,a species Plagiostomum sp.,was collected from East River in Huizhou City(23°09′00.31″N,114°22′26.59″E),Guangdong Province.It was 4.51-6.00 mm long,with 4 eyes,a blunt round head,and a tapered tail.Its body,whose middle part appeared spindle-shaped,was covered with irregular brown fine grain.This flatworm was inactive and showed no response to light stimulation.It could feed on Rhabdocoela and Macrostomida turbellarians.It laid 1 egg per day,and 5-10 larvae were hatched from one egg in 10-15 d;subsequently these larvae matured in 20-25 d at 18-25℃.Histological observation showed that the basement membrane,beneath which there was brown fine grain,was one-third to half the thickness of its ectoderm.The ovary was anterior to testis,and both of them were located in both sides of enteron.Suprisingly,there was no boundary between ovary and testis.Bursa copulat rix,receptaculum seminalis,deferens and oviduct were absent.Extraneous spermatozoa distributed extensively around brain,ovary,mesoblast and endothelium of alimentary canal.Fleshy copulatory apparatus was circled in its sheath.Finally,this paper discussed the taxonomy and distribution of this species.