On the Microanatomy of the Cephalic Nervous System of Nereidae (Polychaeta), with a Preliminary Discussion of Some Earlier Theories on the Segmentation of the Polychaete Brain

Earlier papers dealing with the microanatomy of the nereid brain have been studied. On this basis a re‐investigation of the cephalic nervous system and of the innervation and homologues of the anterior end appendages of these animals appeared necessary: the existing literature proved insufficient fo...

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Bibliographic Details
Published inActa zoologica (Stockholm) Vol. 74; no. 2; pp. 145 - 172
Main Author Orrhage, Lars
Format Journal Article
LanguageEnglish
Published Oxford, UK Blackwell Publishing Ltd 01.03.1993
Elsevier Science
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Summary:Earlier papers dealing with the microanatomy of the nereid brain have been studied. On this basis a re‐investigation of the cephalic nervous system and of the innervation and homologues of the anterior end appendages of these animals appeared necessary: the existing literature proved insufficient for detailed comparisons with other polychaete families and many earlier statements were quite contradictory. In the present paper, the brain commissures and the innervation of, inter alia, the antennae and the palps of Neanthes virens and Nereis pelagica are described. Special attention was paid to the roots of the circum‐oesophageal connectives and the ganglia in this part of the nervous system. The results, summarized in schematic diagrams and tables, are compared with corresponding observations in 14 other polychaete families. In a discussion of the architecture of the polychaete nervous system as a phylogenetic instrument, the supposed segmentation of the polychaete brain is questioned and the idea that the configuration of the polychaete nervous system offers support to the cyclomer theory is rejected. Other conclusions concerning the relationships within the Polychaeta are pointed out.
Bibliography:istex:C34A67370E84B261A9E81D91F9E3A94EEBA98C45
ArticleID:AZO1231
ark:/67375/WNG-LW0C9GXF-P
ISSN:0001-7272
1463-6395
DOI:10.1111/j.1463-6395.1993.tb01231.x