Histological investigations on Dendrodoris nigra (Stimpson, 1855) (Gastropoda, Nudibranchia, Dendrodorididae)

摘要

The histology of the major organ systems (digestive, reproductive, nervous, circulatory, excretory and respiratory, as wdl as epidermis) of the nudibranchDendrodoris nigra(Stimpson, 1855) arc described for the first time and the results are compared with those derived from other members of the Doridoidea. It is shown that some characters which have been used to differentiate the genusDendrodorisEhrenberg, 1831 from other doridoideans (i.e., retractability of gills, lack of hard structures in the anterior digestive system, presence of pericardial glands) are problematic when used for phylogenetic ,analysis. This is especially true when taking into consideration that little is known about details of these structures in the Doridoide, as a whole.