Donacidae
The Donacidae are a family of saltwater clams, marine bivalve mollusks in the order Veneroida. They are commonly known as donax clams, wedge shells, coquina clams, sand clams, or beach clams.
Characteristics
Donacidae have a distinctive wedge-shaped or triangular shell with a rounded posterior end and a pointed anterior end. The shell is generally smooth and glossy, and the hinge line is straight with two prominent cardinal teeth. The siphons are short and separate, and the mantle margin is often fringed with sensory tentacles. They are burrowing bivalves, living in the intertidal zone or just below the surface of the sand. The foot is large and powerful, allowing them to dig rapidly and move around the sand.
Environments
Donacidae are found in a wide range of marine environments, including beaches, estuaries, and coastal lagoons. They prefer sandy substrates, where they can bury themselves to avoid predators and harsh environmental conditions. They are often found in large numbers, forming dense populations in suitable habitats.