''Clypeaster reticulatus'', the reticulated 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 ...

. This species 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 ...

. It lives on the sandy seabed of shallow seas, semi-immersed in the sediment.

Description

The reticulated sea biscuit can grow to a length of about . Like all sea biscuits it is bilaterally symmetrical and tends to be rather irregular in shape. It has a solid but slightly rounded aboral (upper) surface. The

ambulacral Ambulacral is a term typically used in the context of anatomical parts of the phylum Echinodermata or class Asteroidea and Edrioasteroidea. Echinoderms can have ambulacral parts that include ossicles, plates, spines, and suckers. For example, sea ...

areas on the aboral surface are characteristically shaped like petals and are at least two-thirds the width of the test. These are long and inflated, the front one being the longest and the foremost pair being the shortest. The oral (under) surface is concave or cup-shaped, with the food grooves being indistinct and only slightly indented. The anus is located on the underside near the margin at the back. Live specimens are yellowish-grey, often with darker markings, while bare tests are whitish. The

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 ...

emerge through widely spaced pairs of pores and are used in respiration. The pores and tubercles are not linearly arranged; they are irregularly scattered.

Distribution and habitat

This sea biscuit has a widespread distribution in the western Indo-Pacific region. Its range extends from 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''; ...

to Hawaii and from Taiwan to New Caledonia, but it does not occur in Australia. It is found on sandy seabeds 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 .

References

{{Taxonbar, from=Q1984673 Animals described in 1758 Clypeaster Taxa named by Carl Linnaeus