The trochidae family (Mollusca : Gastropoda) in northern Chile: taxonomic and ecological considerations

This study reveals the diversity, and the bathimetric and latitudinal distr ibution of the snails of the Trochidae family members in northern Chile, th roughout the analysis of all Trochidae gastropods entailed in intertidal an d subtidal (from the 'camaron naylon' fishery) samples collected during 199 6 and 1999 between Arica (ca 18 degrees S) and Los Vilos (ca 31 degrees S). The Trochidae family in northern Chile have four genus: Tegula and Diloma that are distributed on intertidal and shallow subtidal habitats, and Calli ostoma and Bathybembix which occurr at dephts greather than 200 m. Tegula h ave 6 species: T. quadricostata, T. luctuosa, T. ignota, T. atra, T. triden tata, and T. euryomphala are distributed on intertidal and shallow subtidal habitats. Diloma is a monospecific genus, whereas D. nigerrima is an inter tidal species. The genus Calliostoma have two species C. chilena and C. del li occurring between 200 and 750 m depth and the Bathybembix with two speci es, B. Humboldti and B. macdonaldi, distributed between 200 and 1480 m dept h. The bathimetric distribution of Trochidae shows a strong correlation wit h food strategy: Diloma and Tegula are herbivores, while Bathybembix specie s are deposit feeders and Calliostoma are carnivores.