''Eupolymnia crassicornis'' is a tropical

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 ...

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

, commonly known as a spaghetti worm. These worms are found mainly near the

Florida Keys The Florida Keys are a coral cay archipelago located off the southern coast of Florida, forming the southernmost part of the continental United States. They begin at the southeastern coast of the Florida peninsula, about south of Miami, and e ...

and

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

. They can be found on the sea bottom near rocks and sand. They live buried in the sand where they create a tube-like structure. They extend their thin white tentacles out of the top of the tube in which they dwell.

Diet

''Eupolymnia crassicornis'' are deposit feeders that primarily feed at evening or night. They extend their ciliated tentacles out and along the sea-floor to gather dead organic matter (detritus) that originated as diatoms and other planktonic microorganisms. The collected detritus is then passed along a groove in their tentacles to their mouth, to be consumed.

Anatomy

External

Spaghetti worms have tentacles that extend outside their burrow for a considerable distance. The bodies of spaghetti worms are segmented. The tentacles can grow over one meter long. The tentacles are used to wrap around their prey and bring it closer to the mouth. ''Eupolymnia crasscornis'' also has inner and outer lips for food gathering. They have adopted this way of life to protect their bodies from

predators Predation is a biological interaction where 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 kill the ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

s and fish. They also share their burrow/home with other creatures such as the tube pea crab ''

Pinnixa chaetopterana ''Pinnixa chaetopterana'', the tube pea crab, is a small decapod crustacean that lives harmlessly within the tube of the polychaete worm, ''Chaetopterus variopedatus''. Description ''P. chaetopterana'' is a tiny, soft-bodied crab. The bodies o ...

'' which they also use for protection. Spaghetti worms use three pairs of branched gills for

breathing Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen. All aerobic creatures need oxygen for cellular ...

Internal

Spaghetti worms have a well-developed gut consisting of an oesophagus, fore-

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

closed circulatory system The blood circulatory system is a organ system, system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascula ...

, hind-stomach and

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...

, and use

enzymes Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

to help carry out

digestion Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intest ...

Reproduction

Spaghetti worms reproduce externally. They have

lecithotrophic Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and mo ...

larvae. Unusually, both males and females have been observed to release gametes even when the other sex was not in the vicinity.

References

*http://www.catalogueoflife.org/ *http://www.thecephalopodpage.org/MarineInvertebrateZoology/Eupolymniacrassicornis.html *http://www.susanscott.net/OceanWatch1998/jan19-98.html {{Taxonbar, from=Q3608003 Terebellida