Abstract

The study of the lophophore organization is of great importance for the reconstruction of lophophorate phylogeny and for understanding the evolutionary transformation in each phylum of Lophophorata. The innervation of the lophophore in ctenostome bryozoan Flustrellidra hispida was studied using immunocytochemistry and confocal laser scanning microscopy. It has been demonstrated that this species has an outer nerve ring giving rise to the tentacle nerves. The outer nerve ring was earlier described in some ctenostomates and cyclostomates, but not as connected with nerves. The discovered feature of lophophore innervation in F. hispida suggests the evolutionary transformation from a hypothetical phoronida-like ancestor lophophore bearing a prominent outer nerve ring with numerous tentacle nerves emanating from it, to the complex bell-shaped lophophore of F. hispida with a well-pronounced outer nervous ring bearing a few tentacle nerves. The next one in this hypothetical row is the lophophore of the other ctenostomates and some cyclostomates with no ring-nerve connection and cheilostomates lophophore with no outer nerve ring at all.

中文翻译：

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Flustrellidra hispida触手神经支配的特性与苔藓虫的Lophophore进化

摘要

海参组织的研究对于重建海参的系统发育和了解海参各门的进化转变具有重要意义。使用免疫细胞化学和共聚焦激光扫描显微镜研究了 ctenostome 苔藓虫Flustrellidra hispida中 lophore 的神经支配。已经证明该物种具有产生触手神经的外神经环。早先在一些栉口动物和环口动物中描述了外神经环，但与神经没有联系。已发现的F. hispida中叶柄神经支配的特征表明从假想的类似佛罗尼达的祖先 lopophore 进化转变为带有突出的外神经环和许多触手神经的F. hispida复杂的钟形 lobophore具有明显的外神经环，带有一些触手神经. 在这个假设行中的下一个是其他栉口动物和一些没有环神经连接的环口动物的 lophophore，以及根本没有外神经环的唇口动物 lophophore。