Macoma

Macoma is a genus of marine bivalve molluscs belonging to the family Tellinidae. These clams are found in a variety of marine habitats worldwide, often inhabiting sandy or muddy substrates in shallow to moderately deep waters. Macoma species are characterized by their relatively thin, equivalve shells, meaning both valves are of similar size and shape. The shells are typically ovate or triangular and can vary in color, often exhibiting shades of white, gray, or pink.

A distinguishing feature of many Macoma species is the presence of a posterior gape, an opening at the back of the shell. This gape allows the clam to extend its siphons, which are tube-like structures used for feeding and respiration, above the sediment surface. Macoma clams are deposit feeders, using their siphons to draw in detritus and small organic particles from the surrounding sediment. They play a role in bioturbation, the disturbance of sediment by living organisms, which can influence nutrient cycling in benthic ecosystems.

Reproduction in Macoma is typically sexual, with external fertilization occurring in the water column. The planktonic larvae eventually settle on the seafloor and metamorphose into juvenile clams. Several species within the Macoma genus are well-known, such as Macoma balthica, which is found in both brackish and marine waters and is ecologically significant in many coastal areas. The genus is ecologically important as a food source for various marine animals, including fish and shorebirds.