Venerids

Venerids, or the family Veneridae, are a diverse group of marine bivalve molluscs commonly known as Venus clams. They live in sandy, muddy, and mixed substrates in coastal and estuarine habitats worldwide, from the intertidal zone to shallow subtidal flats. The shells are typically thick and oval to rounded, with two equally sized valves and a strong hinge. Inner surfaces show large adductor muscles. Venerids are active filter feeders, drawing water through incurrent siphons and extracting plankton and detritus, with water expelled by excurrent siphons; many species burrow in soft sediments using a muscular foot.

Taxonomy and diversity: The Veneridae belongs to the order Veneroida and includes numerous genera such as Mercenaria (hard clams), Ruditapes (Manila clams), Dosinia, Venus, Chione, and Paphia. They are characterized by robust shells, a well-developed hinge with cardinal teeth, and a siphon system for feeding and respiration.

Reproduction and development: Most venerids reproduce by external fertilization, releasing eggs and sperm into the water column. Fertilized eggs develop into free-swimming larvae (veligers) before settling as juveniles.

Ecology and human use: Venerids contribute to water filtration and form a dietary resource for many predators. Several species are commercially important for seafood and aquaculture, notably Mercenaria mercenaria (hard clam) and Ruditapes philippinarum (Manila clam). Populations face pressures from overfishing, habitat loss, and pollution in some regions.

Fossil record and distribution: Venerids have a long fossil record and are widely distributed, especially in temperate and tropical seas.