Physiology of Finfish and Shellfish (2+1)

2.1.34. Respiratory system of gastropods

Introduction

The dorid nudibranch Chromodoris joshi has a rosette of gills far back on the body. Nudibranch means “naked gills”. Near the front of the animal are the two rhinophores.

The respiratory system of gastropods varies greatly in form. These variations were once used as a basis for dividing the group into sub classes. The majority of marine gastropods breathe through a single gill, supplied with oxygen by a current of water through the mantle cavity. This current is U shaped. So that it also flushes waste products away from the anus, which is located above the animals head and would otherwise cause a problem with fouling.

In the pulmonate gastropods, which are found both on land and in freshwater, the gill has been replaced by a simple lung.