Limida

Common Names

Limids are commonly known as file clams due to the shape of their shells, which are often thin and flat, resembling a file. Some species are also referred to as "false scallops" because of their resemblance to true scallops, but this is not a widely used term.

Characteristics

Limids are characterized by the following features:

• Elongate, often thin shells: The shells of limids are typically elongate and thin, with a smooth or slightly sculptured surface. They are often compressed laterally, meaning they are flat from side to side.
• Specialized feeding mechanism: Limids are filter feeders, but they have a unique adaptation for feeding. They have a pair of long, thin siphons that they extend out of their shells to filter water for food. The siphons are often covered in cilia, which help to capture food particles.
• Byssal threads: Limids often attach themselves to rocks or other hard surfaces using byssal threads, which are strong, silky fibers secreted from a gland in the foot.
• Well-developed mantle cavity: The mantle cavity of limids is well-developed and contains the gills, siphons, and other organs.
• Two adductor muscles: Limids have two adductor muscles that close the shells. These muscles are relatively small and weak, and they do not leave distinct muscle scars on the shell.

Environments

Limids are found in a variety of marine environments, including:

• Intertidal zones: Some species of limids are found in the intertidal zone, where they are exposed to air and water on a regular basis.
• Subtidal zones: Most species of limids live in the subtidal zone, below the low tide mark.
• Deep-sea trenches: Several species of limids are found in deep-sea trenches, where they are adapted to live in very high pressures.

References

For more information on Limida, refer to the following websites:

• World Register of Marine Species (WoRMS): https://www.marinespecies.org/aphia.php?p=taxdetails&id=138258
• Encyclopedia of Life: https://eol.org/pages/41663/overview