Mactridae, common name the trough shells or duck clams, is a family of saltwater clams, marine bivalve mollusks in the order Venerida.

Temporal range: Cretaceous to Present
Spisula solida.jpg
Shell of Spisula solida
Scientific classification e
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Subclass: Heterodonta
Order: Venerida
Superfamily: Mactroidea
Family: Mactridae
Lamarck, 1809

See text.


These clams have two short siphons, each with a horny sheath. The shell is shaped like a rounded-cornered equilateral triangle and there is a slight gape at the posterior. Each valve bears two cardinal teeth with four lateral teeth on the right valve and two on the left. The foot is white and wedge-shaped. They mostly inhabit the neritic zone.[1]


Trough shells burrow in sand or fine gravel and never in muddy substrates.[1]


According to the World Register of Marine Species (2012), this family contains 37 genera:[2]


  1. ^ a b Barrett, J. H.; Yonge, C. M. (1958). Collins Pocket Guide to the Sea Shore. London (UK): Collins. p. 156.
  2. ^ Bouchet, Philippe (2012-03-23). "Mactride Lamarck, 1809". WoRMS. World Register of Marine Species. Retrieved 2017-01-25.
  3. ^ a b c d e f g h i j k l Scott, Paul V. "Mactridae". Integrated Taxonomic Information System.
  4. ^ Kong, Lingfeng; Li, Qi; Qiu, Zhaoxing (2007). "Genetic and morphological differentiation in the clam Coelomactra antiquata (Bivalvia: Veneroida) along the coast of China". Journal of Experimental Marine Biology and Ecology. 343: 110–117. doi:10.1016/j.jembe.2006.12.003.
  5. ^ Coan, E. V.; Valentich-Scott, P. (2012). Bivalve seashells of tropical West America. Marine bivalve mollusks from Baja California to northern Peru. pp. 2 vols, 1258 pp.