Fissurella
Fissurella is a genus of small to medium-sized marine snails that are commonly referred to as keyhole limpets. These gastropods are characterized by their distinctive shell shape, which resembles a limpet with a hole or fissure near the apex. This hole serves as an outlet for water and waste, while the limpet’s muscular foot allows it to cling tightly to rocks and other hard surfaces in the intertidal zone.
Common Names
Fissurella species are commonly known as keyhole limpets or slit limpets due to the characteristic hole in their shells. Other names include "false limpets" and "keyhole snails".
Characteristics
Keyhole limpets are generally small to medium-sized snails, typically reaching sizes of 2 to 5 centimeters in diameter. Their shells are typically conical, with a distinct hole or fissure located near the apex. This hole serves as an outlet for water and waste products, allowing the limpet to breathe and excrete without having to detach from its substrate. The shell surface is often smooth or slightly textured, and it may be adorned with colorful patterns or ridges.
Environment
Fissurella species are found in intertidal and subtidal zones along rocky coastlines worldwide. They are typically found in areas with strong wave action, where they cling tightly to rocks and other hard surfaces to avoid being washed away. Keyhole limpets are herbivores and graze on algae and other microscopic organisms that grow on their substrate. They use their radula, a toothed structure in their mouth, to scrape algae off the rock surface.
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