Crown-of-thorns Starfish
Definition
The crown-of-thorns starfish (Acanthaster) is a large, multi-armed starfish covered in venomous spines that feeds on living coral tissue. Widespread in the Indo-Pacific, including Philippine reefs, it is notorious for outbreaks in which dense populations consume coral faster than reefs can regrow, making it one of the most consequential corallivores in coral reef ecology.
Identities (Wikipedia/Wikidata/DBpedia)
- Wikipedia: https://en.wikipedia.org/wiki/Crown-of-thorns_starfish
- Wikidata: https://www.wikidata.org/wiki/Q26634
- DBpedia: N/A
Also Known As
Crown-of-thorns; COTS.
Examples and Analogies
A single adult can strip many square meters of coral per year, so an outbreak swarm behaves like a locust plague transposed to the reef, leaving white feeding scars that trail the moving front like footprints in snow.
Usage Scenarios
Reef managers use crown-of-thorns counts as an indicator in monitoring programs, organize manual removal dives during outbreaks, and study the species to distinguish human-driven outbreaks from natural population cycles.
Strategies
Control relies on early detection and rapid response, injecting individuals with lethal-but-reef-safe solutions such as vinegar or bile-salt preparations, removing animals by hand without chopping them, and conserving natural predators.
Security and Safety Measures
The spines inflict painful, infection-prone wounds, so divers wear protective gloves and avoid contact; population surveys follow protocols that prevent fragmenting animals, which can regenerate.
Historical Context
Major Philippine regional outbreaks have been documented since the 1970s and 1980s, alongside Australian and Pacific episodes that prompted the development of controlled-removal methods now standard in reef management.
Challenges and Controversies
Scientists debate the relative roles of nutrient runoff from land and overfishing of predators in driving outbreaks, and sustained control campaigns strain the budgets of reef managers already confronting coral bleaching.