Limidae
Limidae, commonly known as file shells or file clams, are a family of saltwater bivalve molluscs. These marine organisms are characterized by their thin, fragile, and often brightly colored shells. They are generally small to medium in size, with many species exhibiting a distinctive elongated, fan-shaped shell. Limidae are found in a wide range of marine environments, from shallow intertidal zones to deeper waters.
Characteristics
File shells possess several distinguishing features. Their shells are typically fragile and thin, often exhibiting a smooth, glossy exterior. They are usually elongated and fan-shaped, with a distinct hinge line. The valves (halves of the shell) are joined together by a ligament, a flexible, elastic structure that helps to keep the valves open. The mantle, which secretes the shell, is often brightly colored and may have intricate patterns. Some species have a distinctive fringe of long, hair-like filaments called ctenidia, which aid in feeding and respiration.
Environment
Limidae are found in a variety of marine habitats, including:
- Shallow intertidal zones
- Subtidal areas
- Coral reefs
- Seagrass beds
- Rocky shores
They are typically found attached to rocks, seaweed, or other substrates. Some species are capable of burrowing into sediment.
Feeding
Limidae are filter feeders, meaning they obtain their food by filtering particles from the surrounding water. They use their gills, which are covered in cilia, to trap food particles. These particles include plankton, algae, and detritus.
Reproduction
Limidae are dioecious, meaning they have separate sexes. Fertilization occurs externally, with the male releasing sperm into the water, which is then taken up by the female. The fertilized eggs develop into free-swimming larvae, which eventually settle to the bottom and metamorphose into juvenile clams.