Tectarius

Tectarius is a genus of small to medium-sized marine gastropod mollusks in the family Littorinidae, the periwinkles. Members of this genus are commonly referred to as rock snails and are found in intertidal and shallow subtidal zones. They occupy rocky shores, coral rubble, and, in some regions, mangrove-lined coasts where they graze on the surface film of algae and microorganisms.

The shells of Tectarius species are generally solid and can vary from rounded to elongated in outline. They typically exhibit spiral sculpturing, with cords or ridges that aid in camouflage and stability on exposed substrates. The aperture is operculate, allowing the animal to seal itself inside the shell when stressed by desiccation or predation. Size ranges among species, but they are generally described as small to moderately sized.

Ecology and behavior: Tectarius snails are herbivorous grazers, feeding on biofilm, diatoms, and microalgae scraped from rocks and other hard substrates using their radula. They are well adapted to the variabilities of the intertidal environment, tolerating periodic exposure to air, fluctuating temperatures, and changes in salinity. Their activity patterns are synchronized with tides and weather conditions.

Distribution and diversity: The genus includes multiple described species, primarily associated with tropical and subtropical regions, especially in Indo-Pacific habitats. Taxonomic work within Littorinidae often involves revisions based on both morphological and molecular data, reflecting ongoing discoveries about species boundaries within Tectarius.

See also: Littorinidae, periwinkles, intertidal gastropods.