文档介绍：Chapter 8 Pelagic Mollusca
"brighter than glass, and yet, as glass is, brittle"
Department of Oceanography
References
Lalli, . & Gilmer, . (1989) Pelagic
Snails. The biology of holoplanktonic
gastropod molluscs. Stanford University Press:
Stanford, California.
张福绥, 1964. 中国近海的浮游软体动物 I. 翼
足类、异足类及海蜗牛类的分类研究. 海洋科
学集刊, 5: 125 - 226
Introduction
In the molluscan phylum the holoplanktonic species do
not form a group on their own, but representatives of
various taxonomic groups independently developed a
holoplanktonic way of life. The most important among
them are the so-called 'Pteropoda', an obsolete, but
quite practical name for what is officially indicated as
Mollusca, Thecosomata. Also the many species of the
Heteropoda are holoplanktonic. Finally, a restricted
number of species within the large group of the
Nudibranchia have the same way of life.
Gastropoda(腹足纲)
Opisthobranchia(后鳃亚纲)
Pteropoda(翼足目) Gastropeteridae(腹翼螺
科) Phyllirrhoidae(波叶海牛科) Glaudidae(海
神鳃科)
Prosobranchia(前鳃亚纲)
Heteropoda(异足亚目)Janthiniidae(海蜗牛科)
Pteropoda 翼足类
a pair of parapodium is modified as a
an (fin)
visceral mass are anisomerous
the nerves are not twisted (detorsion)
hermaphrodite
larval stage
Classification
with shell, head indistinct, one pair tentacles
..………………………. Suborder Thecosomata被壳亚目
with one left-handed spiral or straight calcified shell
……………….………………… Euthecosomata真壳部
left handed spiral shell…………...Limacinidae 虎螺科
straight or some what backward bending shell
…………………………….…Cavoliniidae龟螺科
typical form with one cartilaginous inner shell
……..……………………… Pseudothecosomata假壳部
without shell, head distinct, two pairs tentacles
…………………………Suborder Gymnosomata裸体亚目
Limacinidae 螺科
small, thin, fragile left-
handed spiral shell
mantle cavity on dorsal
side
single lobed fin
Limacina
Limacina helicina
Cavoliniidae龟螺科
Shells are straight or slightly curved.
transverse s