- Habitat Regions
- saltwater or marine
- Average depth
- 10 m
- 32.81 ft
- Sexual Dimorphism
- sexes alike
- Range length
- 700 (high) mm
- 27.56 (high) in
Like most echinoderms,reproduces sexually through broadcast spawning. The female releases millions of eggs into the water column that are fertilized by a male's sperm. Fertilized eggs develop into planktonic larvae, which depend on phytoplankton for nutrition while they pass through several developmental stages, from gastrula to bipinnaria to brachiolaria. Near the end of the brachiolaria stage, the larva settles onto a suitable hard surface and metamorphoses into a juvenile starfish. Its arms will begin to develop as it matures. The juvenile starfish begins with 5 arms, which will increase to as many as 21 arms by adulthood.
Crown-of-thorns starfish reproduce by spawning, in which males and females release their gametes into the seawater, where fertilization occurs. Unlike some other starfish, which can reproduce through somatic fission or arm autonomy,is not known to reproduce asexually. There is evidence that releases chemicals that induces spawning in nearby individuals. However, not all individuals in a given population spawn at the same time.
- Mating System
- polygynandrous (promiscuous)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- broadcast (group) spawning
- Breeding interval
- Acanthaster planci breeds once a year.
- Breeding season
- This species breeds in the summer months in the northern and southern hemispheres.
As this asteroid is a broadcast spawner with a planktonic larval stage, there is no parental investment in offspring. (Birkelanci and Lucas, 1990)
- Parental Investment
- no parental involvement
- Average lifespan
- 16 years
- Average lifespan
Juveniles and sub-adults are the most geographically widespread asteroids recorded within the Great Barrier Reef region. One year after settlement onto the reef, newly formed adults migrate great distances over reef habitats. Locomotory behaviors observed in (Engelhardt, et al., 1999; Engelhardt, et al., 2001; Stump, 1996)are typical of predatory starfish. Individuals crawl at the rate of up to 35 cm per minute over coral reefs and rubble, encountering and consuming stony corals by everting the stomach onto the coral substratum and digesting the polyps. Juveniles feed at night on exposed front reef zones, where apparently they are less likely to be noticed by predators, while adults are more commonly seen in protected back reef zones.
This species does not maintain a home range or territory.
Communication and Perception
Like other asteroids, (Clark and Downey, 1992)uses a combination of chemical detection and tactile senses via its tube feet to locate mates, detect its prey, and perceive its environment.
- Other Communication Modes
While developing as larvae in the water column, individuals of this species consume smaller planktonic organisms. As an adult, this asteroid is an opportunistic carnivore, consuming sclerectinian corals, encrusting sessile invertebrates, and dead animals. It feeds by everting its stomach through its mouth onto its prey and digesting the tissues, absorbing the nutrients through the stomach wall. Pocillopora, Acropora, Pavona, and Porites. (Keesing and Lucas, 1992; Moran, 1988a; Pratchett, 2007)consumes most types of Indo-Pacific stony corals, such as
- Animal Foods
- other marine invertebrates
- Plant Foods
The crown-of-thorns starfish is protected from many types of predators by its long, venomous spines, though many adults (up to 60% within a population) may have missing arms, indicating that predation does occur. Juveniles assume more cryptic behaviors, inhabiting crevices and the undersides of ledges. Predators of Charonia tritonis and various fishes in the families Balistidae and Tetraodontidae, which have horny plate-like scales and strong sharp teeth that allow them to remove chunks of tissue from . (Moran, 1988b)include the giant triton shell
This asteroid is a corallivore, almost exclusively consuming live sclerectinian corals. An average sized adult (40 cm) can kill up to 478 square cm of live coral per day through its grazing activities. The crown-of-thorns starfish can be seen as an ongoing disturbance factor on the reef, removing swaths of clonal corals in its path, and opening up bare areas of coral rock for settlement and recruitment of other species of sessile invertebrates. Thus, (Glynn, 1976; Keesing and Lucas, 1992; Wilson, et al., 2008)can be seen to have a role in diversifying the habitat. However, if coral cover is drastically reduced, populations of coral reef specialists (animals that depend exclusively on coral cover for shelter and food) may decrease. Thus the impact of in their environment depends on how abundant they become.
- Onychopygus impavidus, a copepod
- Molucomes ovatus, a copepod
- Anthessius alatus, a copepod
- Stellicola acanthasteris, a copepod
- Stellicomes bisphaerulifer, a copepod
- Synstellicola acanthasteris, a copepod
Economic Importance for Humans: Positive
There are no known economic benefits for humans.
Economic Importance for Humans: Negative
- Negative Impacts
- bites or stings
This species is not listed under any conservation program.
Larissa Ault (author), San Diego Mesa College, Juliet McCardle (author), San Diego Mesa College, Caitlin Sussman (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Renee Mulcrone (editor), Special Projects.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
- Pacific Ocean
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.
an animal that mainly eats meat
uses smells or other chemicals to communicate
active at dawn and dusk
an animal that mainly eats decomposed plants and/or animals
- active during the day, 2. lasting for one day.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- external fertilization
fertilization takes place outside the female's body
union of egg and spermatozoan
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- indeterminate growth
Animals with indeterminate growth continue to grow throughout their lives.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
- oceanic islands
islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- radial symmetry
a form of body symmetry in which the parts of an animal are arranged concentrically around a central oral/aboral axis and more than one imaginary plane through this axis results in halves that are mirror-images of each other. Examples are cnidarians (Phylum Cnidaria, jellyfish, anemones, and corals).
structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.
- saltwater or marine
mainly lives in oceans, seas, or other bodies of salt water.
an animal that mainly eats dead animals
- seasonal breeding
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
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