Preliminary investigation of Vibrio alginolyticus-like bacteria associated with marine nemerteans

A marine bacterium provisionally identified as Vibrio alginoliticus, which is associated withtetrodotoxin production, was isolated from severalspecies of marine nemerteans. The presence of thisbacterium strongly supports the potential use oftetrodotoxins by nemerteans for protection againstingestion by predators or as an agent in their ownpredatory activities. Tetrodotoxins may facilitatethe ability of the nemertean proboscis to subdue preyduring capture. One commensal nemertean speciesappears not to possess the bacterium. This may bedue, in part, to its non-predatory life style.     

Polymorphism in Oerstedia dorsalis (Abilgaard, 1806) revisited

Genetic distance, estimated from electrophoretic variation of six enzyme loci, between three groups of Oerstedia dorsalis specimens which differ in their external morphology shows that one of the varieties should be assigned the rank of species. The genetic differentiation is compared with a multivariate assessment of morphological distance between these forms, and it is concluded that the substantial genetic differentiation between the two species is not reflected in morphological divergence.     

浙江枝吻纽虫吻的形态学研究

采用组织学、电镜技术等手段对浙江枝吻纽虫吻的生物学特性进行了研究,阐述浙江枝吻纽虫吻的结构与其他分枝纽虫吻的组织结构异同.研究结果表明,浙江枝吻纽虫吻为一条长的肌肉组织的管道结构,一端连着头部组织,一端延伸在一个封闭的空腔中.吻腔环肌层与体壁环肌层没有交叉点,但是吻腔壁背面的环肌与体壁背面的环肌通过一束肌肉而交织在一起.在吻壁处富含大量的分泌细胞和神经细胞.当吻离体后,在普通海水中伸缩能维持 2~4 h.