''Limatula hodgsoni'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...

mollusc in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Limidae The Limidae or file shells are members of the only family of bivalve molluscs in the order Limida. The family includes 130 living species, assigned to 10 genera. Widely distributed in all seas from shallow to deep waters, the species are usually ...

, the file shells or file clams. It is native to the seas around Antarctica.

Description

''Limatula hodgsoni'' grows to a length of , a height of and a diameter of . The

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 ** Thin-shell structure Science Biology * Seashell, a hard o ...

is white, oblong, thin, narrow above and somewhat convex; the posterior side is less curved than the anterior. The umbones are central and the ligament area is narrow and diamond-shaped. The valves are sculpted by 30 to 35 squamate ribs separated by grooves slightly narrower than the ribs. The ribs are finely marked by the annual growth lines.

Distribution

''Limatula hodgsoni'' is found on the seabed of the waters around Antarctica at depths down to at least . It is very common in the zone deeper than which is the lower limit for

anchor ice Anchor ice is defined by the World Meteorological Organization as "submerged ice attached or anchored to the bottom, irrespective of the nature of its formation". It may also be called bottom-fast ice. Anchor ice is most commonly observed in fast ...

formation. In some areas, this zone is characterised by a layer of sponge

spicules Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: * Spicule (sponge), small skeletal elements of sea sponges * Spicule (nematode), reproductive structures found in male nematodes ...

and dead mollusc shells a metre or more thick, overgrown by living

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

s. This matrix is a

biodiverse Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

habitat rich in sea anemones,

polychaete worms Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ma ...

hydroids Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish. Some hydroids such as the freshwater ''Hydra'' are solitary, with the polyp attached directly to the substrate. When these produce buds, ...

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a ...

ns and molluscs. ''Limatula hodgsoni'' is the most abundant bivalve mollusc in this habitat and is preyed on by the starfishes ''

Odontaster validus ''Odontaster validus'' is a species of sea star in the family Odontasteridae. Its range includes the Southern Ocean and the seas around the mainland and islands of Antarctica. Description ''Odontaster validus'' can grow to about 10 cm ...

'' and ''

Diplasterias brucei ''Diplasterias brucei'' is a species of starfish in the family Asteriidae. It is found in the Pacific Ocean and Southern Ocean. It is a predator and scavenger and is unusual among starfish in that it broods its young. Description ''D. brucei'' ...

''.

References

{{Taxonbar, from=Q13763375 Limidae Molluscs described in 1907