Acanthaster planci Crown-of-Thorns Starfish

Acanthaster planci Biological Classification Domain: Kingdom: Phylum: Class: Order: Family: Genus: Species: Eukaryota Animalia Echinodermata Asteroidea (sea stars) Valvatida Acanthasteridae Acanthaster (2 species) Acanthaster planci

Echinodermata Characteristics: Bilateral symmetry as larvae Pentaradial symmetry as adults Spiny/bumpy endoskeleton Water vascular system Tube feet

Acanthaster planci Asteroidea Characteristics: up to 50 arms tube feet protrude from the oral surface Multi-directional movement endoskeleton made up of calcium carbonate plates Pedicellariae

Acanthaster planci Crown-of-Thorns Flattened sea star Large central disk 7-23 arms Elongated spines Multi-colors

Acanthaster planci Crown-of-Thorns

Acanthaster planci Anatomy In the aboral surface: - anus - madreporite(s) In the arms : - ambulacral grooves - spines - podium (feet) - digestive glands

Acanthaster planci Distribution & Habitat

Acanthaster planci Reproduction Sexual reproduction A female can release up to 60 million eggs in one season No asexual reproduction

Acanthaster planci Regeneration

Life Cycle

Acanthaster planci Life Cycle

Acanthaster planci Predators

Acanthaster planci Predators

Acanthaster planci The Great Barrier Reef

Acanthaster planci The Great Barrier Reef

Acanthaster planci World Heritage Criteria being an outstanding example representing significant ongoing geological processes, biological evolution and man's interaction with his natural environment; containing unique, rare and superlative natural phenomena, formations and features and areas of exceptional natural beauty; and Providing habitats where populations of rare and endangered species of plants and animals still survive being an outstanding example representing a major stage of the earth’s evolutionary history

Acanthaster planci Outbreaks

Acanthaster planci Effects of Outbreaks

Acanthaster planci OUTBREAKS Recorded Outbreaks 1962 – – date

Acanthaster planci Monitoring

Acanthaster planci Monitoring

Acanthaster planci Effects of Outbreaks 57% of all outbreak reefs lost 30-50% of their coral 1979 – 1991 Outbreak ON AVERAGE the last outbreak episode caused a 3.4 fold increase in the amount of dead coral than normal

Acanthaster planci Natural phenomenon? Female ability to produce 60 million eggs Have outbreaks been ocurring for years? Are human activities responsible for the worsening/increased frequency of outbreaks? Increased nutrient run-off from the land increases the amount of phytoplankton in the water = greater survival of larvae OR Fishing and shell collecting have led to decreased numbers of predators of the crown of thorns Causes of Outbreaks

Acanthaster planci Current Policy No large-scale interference Close monitoring through three major programs

Acanthaster planci Summary …outbreaks can cause significant disturbance to coral reefs over a wide geographic area… despite considerable scientific research, the cause of … outbreaks and the role of human activities as a causal factor are unknown. Consequently management activities are confined to accurately assessing the current extent and intensity of the outbreak, and to providing advice on crown-of-thorns starfish control measures for particular sites.

Acanthaster planci For more information and regular updates visit: and look for “State of the Reef Report” updates

Acanthaster planci Other Sources: