''Mulinia lateralis'', the dwarf surf clam or coot clam, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of small saltwater clam, a

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Mactridae Mactridae, common name the trough shells or duck clams, is a family (biology), family of saltwater clams, marine (ocean), marine bivalve mollusks in the order (biology), order Venerida. Description These clams have two short siphons, each with a ...

. It occurs in the western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

and the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

Description

''Mulinia lateralis'' has a somewhat inflated triangular

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

, with valves that are thin but not brittle. The shell reaches 15 mm in adult size. The anterior end of the shell is rounded, but the posterior end has a distinctive radial ridge giving it an angular look. The outer surface is white or yellowish and somewhat glossy, covered with fine concentric sculpturing. The beaks are prominent and are slightly angled towards the anterior end. The hinge has a small chondrophore, and the ligament joining the valves is internal. The inner surface of the valves is glossy white.

Distribution

''Mulinia lateralis'' is found on the eastern coasts of North America from the north-eastern United States (

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

) southwards to Mexico. It lives shallowly buried in sand or mud on the lower shore and in the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

. It is tolerant of low

salinities Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ...

and is found in estuaries and lagoons.''Mulinia lateralis''
Smithsonian Marine Station a Fort Pierce. Retrieved 2012-01-30. It is sometimes abundant, and as many as 21,000 individuals have been found in a square metre.

Biology

''Mulinia lateralis'' is a

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

. The diet is mainly

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

or other

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic material. Like other bivalve molluscs, the animal raises its

siphon A siphon (; also spelled syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in an inverted "U" shape, which causes a liquid to flow upward, abo ...

s to the surface of the sediment, draws water in though one and expels it through the other, having filtered out nutrient particles in the gills. The sexes are separate in ''Mulinia lateralis''. The female produces up to 2 million eggs at a time, and fertilisation is external. The

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxono ...

larvae disperse as part of the

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and take from 1 to 3 weeks to develop into the pediveliger stage, whereupon they settle and undergo

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and different ...

. The juveniles grow fast and are sexually mature within 2 months.

Ecology

A number of different animals

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

on ''Mulinia lateralis''. These include birds such as the

sanderling The sanderling (''Calidris alba'') is a small wading bird. The name derives from Old English ''sand-yrðling'', "sand-ploughman". The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-colour ...

and

laughing gull The laughing seagull (''Leucophaeus atricilla'') is a medium-sized gull of North America, North and South America. Named for its laugh-like call, it is an opportunistic omnivore and scavenger. It breeds in large colonies mostly along the Atlantic ...

and crabs. The gray sea star (''Luidia clathrata'') selectively feeds on it and the

knobbed whelk The knobbed whelk (''Busycon carica'') is a species of very large predatory sea snail, or in the US, a whelk, a marine gastropod mollusk in the family Busyconidae, the busycon whelks. The knobbed whelk is the second largest species of busycon ...

(''Busycon carica'') is also a major predator. In addition to a variety of salinities, ''Mulinia lateralis'' is able to tolerate other ecologically stressful conditions like temperature extremes and anoxia. ''Mulinia lateralis'' has been found in the European wadden sea, and has the potential to become an invasive alien species due to its high fecundity, short generation cycle of just 60 days, and broad ecological amplitudes.

References

{{Taxonbar, from=Q3016320 Mactridae Bivalves described in 1822