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:
- Darcinia <small>Clark, 1946</small>
- Darina <small>J. E. Gray, 1853</small>
- Allomactra <small>Tomlin, 1931</small>
- Austromactra <small>Iredale, 1930</small>
- Barymactra <small>Cossmann, 1909</small>
- Coelomactra <small>Dall, 1895</small>
- Crassula <small>Marwick, 1948</small>
- Cyclomactra <small>Dall, 1895</small>
- Diaphoromactra <small>Iredale, 1930</small>
- Harvella <small>J. E. Gray, 1853</small>
- Huberimactra <small>Cosel & Gofas, 2018</small>
- Leptospisula <small>Dall, 1895</small>
- Mactra <small>Linnaeus, 1767</small>
- Mactrella <small>J. E. Gray, 1853</small>
- Mactrellona <small>J. G. Marks, 1951</small>
- Mactrinula <small>J. E. Gray, 1853</small>
- Mactromeris <small>Conrad, 1868</small>
- Mactrotoma <small>Dall, 1894</small>
- Maorimactra <small>H. J. Finlay, 1928</small>
- Mulinia <small>J. E. Gray, 1837</small>
- Oxyperas <small>Mörch, 1853</small>
- Pseudocardium <small>Gabb, 1866</small>
- Rangia <small>Desmoulins, 1832</small>
- Sarmatimactra <small>Korobkov, 1954</small>
- Scalpomactra <small>H. J. Finlay, 1928</small>
- Scissodesma <small>Gray, 1837</small>
- Simomactra <small>Dall, 1894</small>
- Spisula <small>J. E. Gray, 1837</small>
- Trinitasia <small>Maury, 1928</small>
- Tumbeziconcha <small>Pilsbry & Olsson, 1935</small>
- Mactrona <small>Marwick, 1952</small>
- Petromactra <small>Saul, 1973</small>
- Resania <small>J. E. Gray, 1853</small>
- Aktschagylia <small>Starobogatov, 1970</small>
- Aliomactra <small>Stephenson, 1952</small>
- Andrussella <small>Korobkov, 1954</small>
- Avimactra <small>Andrusov, 1905</small>
- Caspimactra <small>A. A. Ali-Zade & Kabakova, 1969</small>
- Chersonimactra <small>Paramonova, 1978</small>
- Cryptomactra <small>Andrussow, 1902</small>
- Cymbophora <small>Gabb, 1869</small>
- Eopapyrina <small>Woodring, 1982</small>
- Geltena <small>Stephenson, 1946</small>
- Ionesimactra <small>Signorelli, 2023</small>
- Kirghizella <small>Andrusov, 1902</small>
- Mactrodesma <small>Conrad, 1869</small>
- Mactrona <small>Marwick, 1952</small>
- Mulinoides <small>Olsson, 1944</small>
- Nelltia <small>Stephenson, 1952</small>
- Nymphactra <small>Stilwell & Zinsmeister, 1992</small>
- Ovamactra <small>Woodring, 1982</small>
- Petromactra <small>Saul, 1973</small>
- Planimactra <small>Ionesi, 1986</small>
- Podolimactra <small>Ionesi, 1986</small>
- Praerangia <small>Cossmann, 1908</small>
- Priscomactra <small>Stephenson, 1952</small>
- Pseudomactra <small>Steklov, 1960</small>
- Pteroluter <small>Saul, 1973</small>
- Stereomactra <small>Stewart, 1930</small>
- Stiphromactra <small>Böhm, 1929</small>
- Tenuimactra <small>Garvie, 1996</small>
- Willimactra <small>Saul, 1973</small>
- Zenatiopsis <small>Tate, 1880</small>
References