Crown-of-thorn Starfish

Acanthaster planci

• Phylum: Echinodermata– Calcitic skeleton– Water vascular system– Mutable collagenous tissue– Pentaradial body organization

• Class: Asteroidea– True starfish– Movement with tube feet– Predators

Distribution

Crown of Thorn Starfish

Appearance- 25-35cm, max 80cm

- 12-19 arms

- multicolored - GBR: reddish grey with red-tipped

spines

Behavior

• Habitat– Coral Reefs

• Movement– Tube feet

• Feeding– Digestive enzymes

Life Cycle

• Fertilization– Embryo develops into

larvae; feeds on plankton

• Planktonic stages– At the mercy of the ocean– Gastrula Bipinnaria Brachiolaria– Primordium – sack like structure

Life Cycle

• Settlement– Day 2: Juvenile

starfish– Month 6: about 1 cm

and feeding on coral– Year 2: 20 cm and

sexually mature– Year 3-4: Senile, low

growth and reproduction

Outbreaks

• Natural Hypothesis– Agricultural runoff creating algal blooms

• Man interference– Removal of starfish predators

Outbreaks

• Type– Primary– Secondary

• Duration– 1- 4 Years– GBR 15 Years

GBR Outbreaks

Healthy Habitats

The Evil

• Reef Destruction– 5-6 km yearly– 86% of GBR

• Humans– Poisonous spines

Destroyed Habitats

Containment Problems

• Gamete production– 65 million eggs

• Larval size– Antibodies to track

• Reef size– Needle in a hay stack

Reef Protectors

• Red Spotted Trapeze Crab

• Giant Triton

• Hawaiian Lined Fireworm

• Divers

Red spotted trapeze crab

Giant Triton

Hawaiian Lined Fireworm

Divers

• Cutting– Not practiced

• Injections– Copper sulfate

• Removing– Difficult

Knowledge

• Imprecise Science– 1960’s

• Willingness– Attitude

• Research– GBRMPA

Research

Pictures

References• Google Images

• Crown of thorn starfish Q&A, http://www.aims.gov.au/pages/reflib/cot-starfish/pages/cot-000.html

• www.gbrmpa.gov.au/.../sotr/latest_updates/cots

• http://www.aims.gov.au/pages/reflib/cot-starfish/pages/cot-f15.html

• http://en.wikipedia.org/wiki/Crown-of-thorns_starfish

• Ecological Applications Textbook

• http://www.divegallery.com/crownofthorns.htm

• http://www.tellusconsultants.com/Thread/ACANTH.HTM