Stivaris

Stivaris is a genus of small, marine gastropod mollusks belonging to the family Rissoidae. These snails are typically found in the shallow waters of the Atlantic Ocean, inhabiting sandy or muddy substrates. They are characterized by their small, elongated, and often spiraled shells, which can vary in color from white to brown. The shell surface may exhibit fine striations or ribbing.

The anatomy of Stivaris is typical of prosobranch gastropods, featuring a distinct head with tentacles and a foot adapted for crawling. They are generally detritivores or herbivores, feeding on algae and organic matter found on the seafloor. Reproduction in Stivaris involves the laying of egg capsules, which are attached to the substrate. The larval stage is planktonic, dispersing them to new areas.

While not commercially significant, Stivaris plays a role in the marine ecosystem as a food source for larger invertebrates and fish. Several species are recognized within the genus, with slight morphological differences and geographic distributions. Research into Stivaris often focuses on their ecological role, population dynamics, and evolutionary relationships within the Rissoidae family. Their small size and benthic lifestyle make them a subject of interest for marine biologists studying nearshore environments.