Aerial respiration of nerites from thr north-east coast of Australia

Abstract

Measurements were made of the aerial respiration of Nerita plicata, N. polita and N. albicilla (Molluscs : Gastropoda) collected, after various periods of emersion, from the shores of Heron and Lizard Islands, Queensland, Australia. These observations were correlated with observations of behaviour on the shore and the following pattern of locomotory and respiratory activity was discerned. At the beginning of emersion individuals are conspicuous on the surfaces of the rocks and stones amongst which they live; they crawl actively and respiration is at its highest. As the duration of emersion increases the animals become less conspicuous, retiring under stones and into rock crevices; they become quiescent and respiration is reduced. As the incoming tide reaches the zone occupied by each species activity is resumed and the respiratory rate increases, though not necessarily to the level shown at the start of emersion.

Experimental results varied and indicate that respiration during ernersion is closely related to locomotory activity. Although the species studied were collected from different shore levels, all consumed oxygen at similar rates. This suggests that differences in the ability to respire aerially during emersion are not important in controlling the littoral zonation of these species.