Relations between shell size and radula size in marine prosobranchs (Mollusca: Gastropoda)

Abstract

The Gastropoda presents the highest adaptative radiation among the mollusks. This characteristic allowed the appearance of many forms of feeding, and with it, many strategies of capture and food processing. In this work, specimens belong to 14 marine prosobranch gastropod species were collected in the coast of Ceará State Northeast Brazil with the purpose to investigate the relation between shell size and radula size in gastropods with different diets and radula type. It was found significative correlations in Cerithium atratum, Collisella subrugosa, Fissurella rosea, Neritina virginea, Olivella minuta, Pisania pusio, Tegula viridula, and Thais haemastoma. Nonsignificative results were found in Littorina flava, Littorina ziczac, Nassarius vibex, Natica marochiensis, Pleuroploca aurantiaca, and Pugilina morio. The species with rhipidoglossate radula and the driller carnivores with rachiglossate radula are the ones that presented significative correlation among shell size and radula size. Other parameters that could influence the radular morphology (besides the radula type or diet) are environment pressure, prey searching and capture strategies and species ontogeny