''Limaria fragilis'', the fragile file clam, is a
species
In biology, a species is the basic unit of 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 the appropriate s ...
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, bival ...
mollusc in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
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 usua ...
. It is found in shallow waters in the Indian and Pacific Oceans and has the ability to swim.
Description
The fragile file clam has a pair of hinged, thin, asymmetric white valves and a red mantle with a fringe of long tapering pink and grey banded tentacles at its edge. Also around the margin of the mantle are a row of tiny eyespots that can detect light and shade, and may alert the animal to the approach of a predator.
[''Limaria fragilis'']
Saltcorner. Retrieved 2012-04-20.
Distribution and habitat
The fragile file clam is widely distributed in the
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth.
In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
region. Its range includes the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
, the
Marshall Islands
The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Internati ...
, the
Cook Islands
)
, image_map = Cook Islands on the globe (small islands magnified) (Polynesia centered).svg
, capital = Avarua
, coordinates =
, largest_city = Avarua
, official_languages =
, lan ...
,
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
, the
Chagos Archipelago
The Chagos Archipelago () or Chagos Islands (formerly the Bassas de Chagas, and later the Oil Islands) is a group of seven atolls comprising more than 60 islands in the Indian Ocean about 500 kilometres (310 mi) south of the Maldives archi ...
,
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
and the
Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...
.
[ It often conceals itself in crevices or under stones with just its tentacles protruding.][
]
Biology
The fragile file clam is a protandrous hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...
. Juveniles start life as males and change sex to females as they grow. Fragile file clams have the ability to emit flashes of biolumiscent light, though why they do this is unclear.[
The fragile file clam can swim slowly and continuously for about 5 minutes at a time.]jet propulsion
Jet propulsion is the propulsion of an object in one direction, produced by ejecting a jet of fluid in the opposite direction. By Newton's third law, the moving body is propelled in the opposite direction to the jet. Reaction engines operating o ...
. In an aquarium, the animal flits around knocking into other objects.[ It uses its mantle tentacles in an oar-like fashion when swimming. Sometimes it ]sheds
A shed is typically a simple, single-story roofed structure that is used for hobbies, or as a workshop in a back garden or on an allotment. Sheds vary considerably in their size and complexity of construction, from simple open-sided ones de ...
the longest tentacles and can still swim effectively without them, increasing the frequency of valve clapping to maintain speed. The detached tentacles secrete a noxious substance and continue to writhe after they are severed which may distract aggressors.glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH ...
and arginine phosphate. Further study showed that this was not the case. There was a high level of arginine kinase and certain other enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
s in the adductor muscles which was indicative of the conversion of arginine phosphate for energy production. Up to 23% of the ATP used for energy transfer was supplied in this way while the animal was swimming.[
]
References
External links
*
{{Taxonbar, from=Q6548889
Limidae
Bivalves described in 1791
Taxa named by Johann Friedrich Gmelin