brittle star

brittle star
any echinoderm of the class Ophiuroidea, having the body composed of a central, rounded disk from which radiate long, slender, fragile arms.
Also, brittlestar. Also called serpent star.
[1835-45]

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▪ class of echinoderms
also called  serpent star 
 any of the 2,100 living species of marine invertebrates constituting the subclass Ophiuroidea (phylum Echinodermata). Their long, thin arms—usually five and often forked and spiny—are distinctly set off from the small disk-shaped body. The arms readily break off but soon regrow—i.e., are regenerated. Among the basket stars, a type of brittle star, each arm may branch multiple times, and the outstretched arms reach nearly 1 metre (about 3 feet) across. Most basket stars live in deep water.

      The mouth, on the underside of the body, has five teeth; an anus is lacking; and the tube feet serve mainly as sense organs for detecting light and odour. The animal feeds by extending one or more arms into the water or over the mud, the other arms serving as anchors. Brittle stars are mainly deposit feeders, scavengers, and plankton feeders; however, they sometimes trap sizable animals. They are capable of moving jerkily but usually cling to the seafloor or to sponges or cnidarians (e.g., coral).

      Brittle stars occupy many marine habitats, often at great depths. The most widespread species is the long-armed brittle star (Amphipholis squamata), a grayish or bluish species that is strongly luminescent (bioluminescence). Two of the best-known littoral species are the green brittle star (Ophioderma brevispina), found from Massachusetts to Brazil, and the common European brittle star (Ophiothrix fragilis). Brittle stars typically hide under rocks or in crevices during the day and emerge at night to feed.

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Universalium. 2010.

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Look at other dictionaries:

  • Brittle star — Temporal range: 488.2–0 Ma …   Wikipedia

  • Brittle star — Brit tle star (br[i^]t t l st[aum]r ), (Zo[ o]l.) Any species of ophiuran starfishes. See {Ophiuroidea}. [1913 Webster] …   The Collaborative International Dictionary of English

  • brittle star — n. any of a subclass (Ophiuroidea) of echinoderms having a central disk and five long, narrow, easily breakable arms that can quickly regenerate …   English World dictionary

  • brittle star — noun an animal resembling a starfish with fragile whiplike arms radiating from a small central disc • Syn: ↑brittle star, ↑serpent star • Hypernyms: ↑echinoderm • Member Holonyms: ↑Ophiurida, ↑subclass Ophiurida * * …   Useful english dictionary

  • brittle-star — noun an animal resembling a starfish with fragile whiplike arms radiating from a small central disc • Syn: ↑brittle star, ↑serpent star • Hypernyms: ↑echinoderm • Member Holonyms: ↑Ophiurida, ↑subclass Ophiurida …   Useful english dictionary

  • brittle star — brit′tle star or brit′tle•star n. ivt any echinoderm of the class Ophiuroidea, having the body composed of a central rounded disk from which radiate long, slender, fragile arms • Etymology: 1835–45 …   From formal English to slang

  • brittle star — noun Date: 1843 any of a class or subclass (Ophiuroidea) of echinoderms that have slender flexible arms distinct from the central disk …   New Collegiate Dictionary

  • brittle star — noun any of various echinoderms, of the class Ophiuroidea, that resemble starfish and have long, slender arms that regenerate when snapped off …   Wiktionary

  • brittle-star — /ˈbrɪtl sta/ (say britl stah) noun a starfish of the class Ophiuroidea, having slender arms sharply marked off from the central disc …  

  • brittle — adj. & n. adj. hard and fragile; apt to break. n. a brittle sweet made from nuts and set melted sugar. Phrases and idioms: brittle bone disease = OSTEOPOROSIS. brittle star an echinoderm of the class Ophiuroidea, with long brittle arms radiating… …   Useful english dictionary

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