Common name: Crown Of Thorns Sea Star
General information
The Crown-of-Thorns Starfish (COTS), Acanthaster planci, is a notorious coral predator found in coral reef ecosystems. It is known for its potential to cause significant damage to coral reefs during population outbreaks. This starfish has a unique appearance with its thorny exterior and can grow up to 60 centimeters in diameter.
Details
- Recommended minimum tank volume
- 1,000 liter (260 gallons)
- Salinity
- S.G. 1.023 to 1.025
- Temperature
- 22 to 28 °C (72 to 82 °F)
- Acidity
- pH 8 to 8.4
- Average size
- 40 cm (1′4″)
- Care level
- Very difficult Requires large, predator-only systems.
- Diet
- Carnivore Feeds on coral polyps, risky in reefs.
- Reefsafe
- No Eats live corals, not reef-compatible.
- Aggression
- Semi aggresive Harmful to corals, not to fish.
- Captive bred
- No
Taxonomy
- KingdomAnimalsAnimalia
- PhylumEchinodermsEchinodermata
- ClassStarfishAsteroidea
- OrderStarfishValvatida
- FamilyCrown-of-Thorns StarfishAcanthasteridae
- GenusCrown-of-Thorns StarfishAcanthaster
- SpeciesCrown Of Thorns Sea StarAcanthaster planci (Linnaeus, 1758)
- SynonymsAcanthaster echinites (Ellis & Solander, 1786)Acanthaster echinus Gervais, 1841Acanthaster ellisi (Gray, 1840)Acanthaster ellisi pseudoplanci Caso, 1962Acanthaster mauritiensis de Loriol, 1885Acanthaster pseudoplanci Caso, 1962Acanthaster solaris Schreber, 1793Asterias echinites Ellis & Solander, 1786Asterias echinus Gervais, 1841Asterias planci Linnaeus, 1758Asterias solaris Schreber, 1793Echinaster ellisi Gray, 1840Echinaster solaris Schreber, 1793Echinities solaris Schreber, 1793Stellonia echinites L. Agassiz, 1836
Care
In the aquarium, COTS are not recommended for most hobbyists due to their coral-eating habits. However, for those with a predator or species-specific tank, care should focus on providing a large tank with ample live rock for hiding and foraging. It is crucial to monitor their interaction with other tank inhabitants, as they can decimate coral populations.
Reproduction
Crown-of-Thorns Starfish are prolific breeders, releasing large quantities of eggs and sperm into the water column where external fertilization occurs. They can rapidly increase in number under favorable conditions, which contributes to their outbreak potential in the wild.
Symbiosis
While not typically involved in beneficial symbiotic relationships, COTS can indirectly affect symbiotic dynamics in reef ecosystems by preying on corals, which can alter the habitat structure and the availability of resources for other organisms.
Habitat
Acanthaster planci is found in the Indo-Pacific region, from the Red Sea and the East African coast across to the Central Pacific Ocean. They inhabit coral reefs and prefer shallow waters but can be found at depths of over 60 meters.