''Clypeaster rosaceus'', the fat sea biscuit,
[ is a species of sea urchin 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 ...
Clypeasteridae
Clypeasteridae is a family of sea urchins in the order Clypeasteroida. This family was first scientifically described in 1835 by the Swiss-American biologist Louis Agassiz.
Genera
The World Register of Marine Species list the following genera a ...
. It occurs in shallow water in the western Atlantic Ocean and was first scientifically described
A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...
in 1758 by Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
.
Description
This is a very large sea biscuit with a strong inflated test
Test(s), testing, or TEST may refer to:
* Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities
Arts and entertainment
* ''Test'' (2013 film), an American film
* ''Test'' (2014 film), ...
, growing to a maximum length of around . In shape it is ovate to slightly pentagonal, with the margin thicker at the anterior end. The petaloid area is broad, the anterior (front) petal being longer than the two posterior, paired petals, which are all of equal length; the area between the pores is wide and raised above the rest of the aboral (upper) surface. The oral (under) surface is fairly flat, with a deep depression around the mouth, and with deeply indented food grooves. The anus is on the oral surface near the posterior margin. The spines are short and coarse. When alive, this species is a dark brown colour, while the bare test is whitish.Kunstformen der Natur
(known in English as ''Art Forms in Nature'') is a book of lithographic and halftone prints by German biologist Ernst Haeckel.
...
'' (1904)
Image:Clypeaster rosaceous.jpg, Preserved test in the Natural History Museum
A natural history museum or museum of natural history is a scientific institution with natural history collections that include current and historical records of animals, plants, fungi, ecosystems, geology, paleontology, climatology, and more. ...
(London
London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
).
Distribution and habitat
The species is found in the western Atlantic Ocean. Its range extends from South Carolina to the West Indies, Barbados, Texas and Venezuela. It is found on soft sandy bottoms, particularly in seagrass meadow
A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...
s, from the littoral zone
The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal a ...
down to about .[
]
Ecology
''C. rosaceus'' lives on the surface of sandy seabeds and is nocturnal. It feeds on fragments of dead plant material and algae particularly among seagrass plants. In the process of feeding it grinds up sand particles with its Aristotle's lantern mouthparts, and it has been estimated that it reduces of coarse particles of sediment into fine particles in the course of a year. During the daytime it is inactive and buries itself or covers its test with fragments of shell and pieces of seagrass, holding these in place with its tube feet
Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on br ...
.[
In Panama, breeding takes place annually in the rainy season, with spawn being liberated into the sea. The eggs contain much yolk to sustain the developing larvae, which settle on the seabed and undergo metamorphosis after about six days.]
References
External links
{{Taxonbar, from=Q2901772
Animals described in 1758
Clypeaster
Taxa named by Carl Linnaeus
_3.jpg.html){kind=link}