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Form and function: size of radular teeth and inorganic content of faeces in a guild of grazing molluscs at Rottnest Island, Western Australia

Black, R., Lymbery, A. and Hill, A. (1988) Form and function: size of radular teeth and inorganic content of faeces in a guild of grazing molluscs at Rottnest Island, Western Australia. Journal of Experimental Marine Biology and Ecology, 121 (1). pp. 23-35.

Link to Published Version: http://dx.doi.org/10.1016/0022-0981(88)90021-4
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Abstract

The size of the cusps of the prominent radular tooth of seven species of molluscs which live on the vertical rocky shores of Rottnest Island varied directly with the size of conspecific individuals, but showed considerable differences between species. Siphonaria kurracheensis, a pulmonate limpet, had much smaller teeth, and Nerita atramentosa, a nerite, had much larger teeth than other species of similar size of body. Although all seven species gained food by scraping algae from the rock, > 80% of the faeces of the chiton Clavarizona hirtosa, the nerite, and the littorine Nodilittorina australis were inorganic materials, probably superficial layers of rock. The mean rate of production of inorganic material in faeces in these seven species was directly and closely related to the mean size of the cusps of the radular teeth. One interpretation of this relationship is that it may predict the outcome of competitive interactions between species which live at the same level of the shore. The superior competitor would be the species with the greater rate of egestion of inorganic material relative to the size of the cusps of its teeth and weight of its body, as has been shown for Collisella and Siphonaria. However, other studies suggest that behaviour and the nature of the surface of the rock may over-ride grazing abilities to influence the outcome of some competitive interactions.

Publication Type: Journal Article
Publisher: Elsevier BV
URI: http://researchrepository.murdoch.edu.au/id/eprint/2508
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