後鰓腹足類の被鰓類(Tectibranchia)と裸鰓類(Nudibranchia)との2,3の相違点について

概要

論文の詳細を見る
Except for the hyperstrophy, the structure of the larval shell (newly hatched) of Philine (tectibranchs) is not different foundamentally from that of prosobranchs. On the other hand, in the larval shell of Duvaucelia (nudibranchs), the formation of the whorl tube (helichocone) is incomplete, so that the shell has neither columella nor umbilicus in usual senses. As Thompson has criticized Thorson's classification of the larval shell of nudibranchs, type A can not be recognized, but Thompson's type 1 ( = Thorson's type B) also can not be recognized to be idetical to the "normal" spiral shell of tectibranchs. The fate of the larval kidney after metamorphosis and its colouration are also different in tectibranchs and nudibranchs respectibely. The remnant of this organs of Philine (tectibranchs) remaines through out the life of the animal, while in nudibranchs, the organ degenerates and disappears after metamorphosis. The larval kidney of tectibranchs is a densely pigmented vesicle, while that of nudibranchs is colourless and transparent. It is interesting to find that among tectibranchs, anaspideans have colourless organs, and among nudibranchs (s.L), sacoglossans show either colourless or pigmented vesicles.
日本動物分類学会の論文
1966-08-30