crown-of-thorns starfish

/krown"euhv thawrnz"/
a starfish, Acanthaster planci, that feeds on living coral polyps, causing erosion and destruction of coral reefs. Also called crown of thorns.

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Reddish and heavy-spined starfish (Acanthaster planci) that has 12–19 arms and is often 18 in.

(45 cm) across. It feeds on the polyps of coral. Beginning с 1963, its population on Australia's Great Barrier Reef exploded. Destruction of coral reefs and islands was feared, and intensive efforts were made to kill it off. Since then other outbreaks have been recorded throughout the southern Pacific. The cause of the outbreaks is unknown, but several factors have been proposed, such as the decimation of the starfish's chief predator, the Pacific triton (a marine snail), by shell collectors. Other factors, including the runoff of nutrient-rich soil into reef waters as a result of shorefront development, have also been implicated. Population fluctuations could also be a feature of the starfish's natural ecology, and human influence may alter these cycles.

Crown-of-thorns starfish

A. Giddings
Bruce Coleman Inc.

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 (Acanthaster planci), reddish and heavy-spined species of the phylum Echinodermata. The adult has from 12 to 19 arms, is typically 45 centimetres (18 inches) across, and feeds on coral (coral reef) polyps. Beginning about 1963 it increased enormously on Australia's Great Barrier Reef. The population explosion was attributed to the decimation of its chief predator, a large marine snail, the Pacific triton (Charonia tritonis), by shell collectors. Thereafter, the starfish multiplied throughout the southern Pacific (to Hawaii about 1970), seemingly threatening the destruction of coral reefs and islands.

      Concern among scientists and environmentalists prompted an attempt to control the animals' proliferation; many were killed by injection with formaldehyde, while others were simply removed from the reefs and destroyed. In the late 1970s, however, new research data indicated that similar expansions, or blooms, had occurred previously, followed by periods of decline. Thus, it seemed likely that the sudden growth of the starfish population during the 1960s represented a phase in the organism's natural cycle. Most outbreaks last one to two years, although some have persisted for as long as five years. What causes these dramatic population explosions is unknown; however, authorities hypothesize that the periodic input of high-nutrient loads from land sources and removal of species that prey on adult starfish may be responsible.

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Universalium. 2010.

Look at other dictionaries:

  • Crown-of-thorns starfish — On a reef in Fiji, 2005. Scientific classification Kingdom …   Wikipedia

  • crown-of-thorns starfish — see crown of thorns II * * * /krown euhv thawrnz / a starfish, Acanthaster planci, that feeds on living coral polyps, causing erosion and destruction of coral reefs. Also called crown of thorns. [1960 65] * * * crown of thorns starfish «KROWN uhv …   Useful english dictionary

  • crown-of-thorns starfish — see crown of thorns …   New Collegiate Dictionary

  • crown-of-thorns starfish — /ˌkraʊn əv θɔnz ˈstafɪʃ / (say .krown uhv thawnz stahfish) noun a starfish, Acanthaster planci, having sharp, stinging spines on the top surface of the body and arms; widely distributed in tropical waters and particularly abundant on the Great… …   Australian English dictionary

  • crown of thorns — n. 1. a coral eating starfish (Acanthaster planci) of the tropical Pacific region, having arms covered with long spines: also crown of thorns starfish or crown of thorns 2. a shrub (Euphorbia milii) of the spurge family, having long spines and… …   English World dictionary

  • crown of thorns — noun 1. somewhat climbing bushy spurge of Madagascar having long woody spiny stems with few leaves and flowers with scarlet bracts • Syn: ↑Christ thorn, ↑Christ plant, ↑Euphorbia milii • Hypernyms: ↑spurge • Member Holonyms: ↑Euphorbia …   Useful english dictionary

  • Crown of Thorns (disambiguation) — Contents 1 Religion 2 Biology and Botany 3 Music 4 Other …   Wikipedia

  • crown of thorns — 1. a climbing spurge, Euphorbia milii splendens, of Madagascar, having stems covered with spines. 2. See crown of thorns starfish. 3. a painful burden, as of suffering, guilt, anxiety, etc.: from the wreath of thorns placed on Jesus head to mock… …   Universalium

  • crown of thorns — Date: 1964 a starfish (Acanthaster planci) of the Pacific region that is covered with long spines and feeds on coral polyps sometimes causing destruction of coral reefs called also crown of thorns starfish …   New Collegiate Dictionary

  • crown of thorns — crown′ of thorns′ n. 1) pln a climbing spurge, Euphorbia milii splendens, of Madagascar, having spiny stems and flowers with petallike red bracts 2) ivt Also, crown′ of thorns′. a starfish, Acanthaster planci that feeds on living coral polyps,… …   From formal English to slang

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