: Many species possess numerous small pallial eyes along their mantle margin, particularly on the posterior side, providing light sensitivity. Lifestyles : They exhibit two main ecological habits:
: Attached to hard surfaces (rocks, coral) via strong byssal threads . Infaunal : Buried in sand or mud. Economic and Ecological Importance arcidae
The family, commonly known as ark shells , is a diverse group of marine bivalve mollusks. These organisms are recognized by their distinct trapezoidal, ribbed shells and a taxodont hinge (characterized by many small, similar teeth). While primarily found in tropical and warm temperate shallow waters, they occupy a wide range of habitats—from coral reefs and rocky substrata to muddy estuarine environments. Taxonomy and Global Distribution : Many species possess numerous small pallial eyes
: Maximum species diversity occurs in the Indo-West Pacific region, where over 180 valid species in more than 30 genera are recorded. Regional Presence : Tropical West Africa : ~27 species. West Atlantic : ~20 species. Northeastern Atlantic : ~10 species. Taxonomy and Global Distribution : Maximum species diversity
: A long, straight hinge line with numerous small teeth.