Rissoidae
Rissoidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Rissoidea. They are commonly known as Risso’s snails or Rissoid snails. Members of this family are generally small, with most species being less than 10 mm in length, and some as small as 2 mm. They are typically white, brown, or yellowish in color, often with a patterned shell.
Characteristics
Rissoid snails have a distinctive, generally high-spired shell with a rounded aperture. The shell surface can be smooth, ribbed, or sculptured with various patterns. The operculum, a small, hard plate that closes the aperture, is typically present and usually has a spiral shape.
Environments
Rissoid snails are found worldwide in marine environments, from the intertidal zone to deep-sea habitats. They are typically found on rocky shores, in sand and gravel, and on seaweeds. Some species are associated with specific habitats, such as coral reefs or hydrothermal vents.
Diet and Behavior
Rissoid snails are herbivorous, feeding primarily on algae and detritus. They use their radula, a ribbon-like structure with rows of teeth, to scrape food from surfaces.
Classification and Taxonomy
The family Rissoidae contains over 1,000 described species, grouped into numerous genera. This diversity is reflected in the varied morphology of Rissoid shells, making accurate identification challenging. Some of the most well-known genera include:
- Rissoa
- Alvania
- Cingula
- Setia
References
For further information on Rissoidae, consult the following resources: