Mactridae, common name the trough shells or duck clams, is a family of saltwater clams, marine bivalve mollusks in the order Venerida.
Description
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.
Ecology
Trough shells burrow in sand or fine gravel and never in muddy substrates.
Subfamilies and genera
According to the World Register of Marine Species (2025), this family contains 56 genera and is split into the following subfamilies:
Subfamily Darininae
- †Darcinia Clark, 1946
- Darina J. E. Gray, 1853
Subfamily Lutrariinae
- Eastonia J. E. Gray, 1853
- Heterocardia Deshayes, 1855
- Lutraria Lamarck, 1799
- Meropesta Iredale, 1929
- Standella J. E. Gray, 1853
- Tresus J. E. Gray, 1853
- Zenatia J. E. Gray, 1853
- Zenatina Gill & Darragh, 1963
Subfamily Mactrinae
- †Allomactra Tomlin, 1931
- Austromactra Iredale, 1930
- Barymactra Cossmann, 1909
- Coelomactra Dall, 1895
- Crassula Marwick, 1948
- Cyclomactra Dall, 1895
- Diaphoromactra Iredale, 1930
- Harvella J. E. Gray, 1853
- Huberimactra Cosel & Gofas, 2018
- Leptospisula Dall, 1895
- Mactra Linnaeus, 1767
- Mactrella J. E. Gray, 1853
- Mactrellona J. G. Marks, 1951
- Mactrinula J. E. Gray, 1853
- Mactromeris Conrad, 1868
- Mactrotoma Dall, 1894
- Maorimactra H. J. Finlay, 1928
- Mulinia J. E. Gray, 1837
- Oxyperas Mörch, 1853
- †Pseudocardium Gabb, 1866
- Rangia Desmoulins, 1832
- †Sarmatimactra Korobkov, 1954
- Scalpomactra H. J. Finlay, 1928
- Scissodesma Gray, 1837
- Simomactra Dall, 1894
- Spisula J. E. Gray, 1837
- Trinitasia Maury, 1928
- Tumbeziconcha Pilsbry & Olsson, 1935
- Mactrona Marwick, 1952
- Petromactra Saul, 1973
Subfamily Resaniinae
- Resania J. E. Gray, 1853
Subfamily Tanysiphoninae
- Tanysiphon W. H. Benson, 1858
Incertae sedis
References
- Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
