Ceratostoma

Common Names

The common name "hornmouth" refers to the prominent, horn-shaped siphonal canal that extends from the apex of the shell. Other common names include "cerith," "winkle," and "dog whelk."

Characteristics

Ceratostoma species are characterized by their robust, heavy shells with pronounced spines or nodules along the whorls. These spines provide camouflage and protection against predators. The shells are typically brown, grey, or white in color and often exhibit intricate patterns of bands or blotches. The operculum, a hard plate covering the opening of the shell, is horny and has a central nucleus.

These snails possess a radula, a ribbon-like structure with rows of teeth that is used for scraping and tearing prey. The foot is large and muscular, allowing them to crawl and cling to rocks and seaweed. They have a siphon, a tube-like structure used for drawing in water, which is essential for respiration and locating prey.

Environment

Ceratostoma species are found in a variety of marine environments, including intertidal zones, subtidal reefs, and rocky shores. They are typically found in areas with strong currents and wave action, where they can attach themselves to solid surfaces. Their preferred habitats include rocky shores, kelp forests, and seagrass beds.

Distribution

Ceratostoma species are found in the northern hemisphere, including the North Atlantic Ocean, the North Pacific Ocean, and the Mediterranean Sea.

Species

The genus Ceratostoma includes several species, including:

• Ceratostoma foliatum (Gmelin, 1791) - Common Hornmouth, found along the Atlantic coast of North America
• Ceratostoma nuttalli (Conrad, 1837) - Nuttall's Hornmouth, found along the Pacific coast of North America
• Ceratostoma fimbriatum (Lamarck, 1822) - Fringed Hornmouth, found in the Mediterranean Sea
• Ceratostoma laeve (Gmelin, 1791) - Smooth Hornmouth, found in the North Atlantic Ocean

References

World Register of Marine Species
The American Malacological Bulletin
ResearchGate