Quick answer
Crown-of-thorns starfish at a glance
The crown-of-thorns starfish (Acanthaster planci) is a marine animal in the family Acanthasteridae. Range in Indonesia: Coral reefs throughout Indonesia, from Aceh to Papua; outbreaks recorded in Sulawesi (e.g. Togean, Sombori) and Kalimantan. Diet: living hard corals, especially Acropora; a carnivore.
| Scientific name | Acanthaster planci |
|---|---|
| Indonesian name | Bintang laut mahkota duri |
| Group | Marine |
| Family | Acanthasteridae |
| Range in Indonesia | Coral reefs throughout Indonesia, from Aceh to Papua; outbreaks recorded in Sulawesi (e.g. Togean, Sombori) and Kalimantan |
| Linked habitats | Coral Reefs |
| Diet | Living hard corals, especially Acropora |
| Range in Indonesia | Coral reefs; recorded in Sulawesi, Kalimantan and Banten |
| Key feature | Large, many-armed body covered in long, sharp venomous spines |
| Other names | COTS; lipan laut, tayomo (local Indonesian names) |
| Risk to people | Venomous spine wounds: pain, swelling, nausea and vomiting |
| Body diameter | Usually 28–41 cm across depending on locality; individuals over 60 cm have been recorded · Marine Biology — Uthicke et al. (2024), The crown-of-thorns seastar species complex |
| Diet type | Carnivore (meat-eater) — hard-coral polyp eater (corallivore) · Animal Diversity Web |
| Reproduction | Laying eggs (oviparous) · Animal Diversity Web |
| Venom or poison | Venomous · Lee et al. 2013, Hemolytic activity of venom from crown-of-thorns starfish Acanthaster planci spines (J Venom Anim Toxins Incl Trop Dis) |
| Active | Nocturnal (active at night) — Large individuals and outbreak populations may also feed by day. · Ling et al. 2020, Homing behaviour by destructive crown-of-thorns starfish is triggered by local availability of coral prey, Proceedings of the Royal Society B (abstract via Europe PMC) |
In this guide (12)
What is the crown-of-thorns starfish?
The crown-of-thorns starfish is a large, coral-eating starfish covered in long, sharp, venomous spines. All Indo-Pacific populations were once treated as one species, Acanthaster planci. Genetic and morphological studies have since revealed at least four species: A. planci in the northern Indian Ocean, A. mauritiensis in the southern Indian Ocean, A. benziei in the Red Sea and A. cf. solaris in the western and central Pacific. Uthicke and colleagues (2024) treat populations in Sulawesi and Kalimantan as A. cf. solaris, while in western Indonesia A. planci and A. cf. solaris occur together. WoRMS still lists A. solaris as a synonym of A. planci, so the older name remains common.
Evidence: Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗ · WoRMS — Acanthaster solaris (Schreber, 1793) ↗ · PeerJ (2023, via PMC) — Crown-of-thorns starfish spines secrete defence proteins ↗
Where does the crown-of-thorns starfish live?
Crown-of-thorns starfish live on coral reefs throughout the Indo-Pacific, including Indonesia. They are usually scarce, but their numbers sometimes explode. The 2024 review by Uthicke and colleagues lists outbreaks in Sulawesi and Kalimantan. In the Togean Islands National Park, Central Sulawesi, residents call the starfish lipan laut and regard it as a reef pest. A 2024 study found 36–117 individuals in the Sombori Islands off Sulawesi, but none at its survey stations in Wakatobi. At Tunda Island in Serang Regency, Banten, one study judged their numbers to be natural and not yet a threat to the reef.
Evidence: Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗ · Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗ · Biodiversitas (2024) — Analysis of environmental parameters supporting the abundance of Acanthaster planci in the Wakatobi and Sombori Marine Protected Areas, Sulawesi, Indonesia ↗
What does the crown-of-thorns starfish eat?
Adult crown-of-thorns starfish feed on the living tissue of hard corals. Acropora corals, including branching and table corals, are usually the preferred prey, but once these are gone other corals are eaten too. According to the 2024 review by Uthicke and colleagues, one adult can consume 161–678 cm² of coral a day and feeds mostly at night. Densities above 10 starfish per hectare are thought to be enough to deplete the coral. Juveniles first graze biofilms and crustose coralline algae, then switch to coral after about 140 days.
Evidence: Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗ · Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗
Why do crown-of-thorns starfish populations explode?
Crown-of-thorns populations can explode because the animals are extremely fertile and their larvae can survive a long time at sea. The 2024 review by Uthicke and colleagues says a single A. cf. solaris female can produce more than 100 million eggs. The larvae drift as plankton for 9–11 days, or more than 40 days when food is scarce, and then settle on crustose coralline algae. Individuals can spawn for the first time at about two years old. The two main suspected causes of outbreaks are fewer predators due to overfishing and nutrient runoff from land that feeds the phytoplankton the larvae eat.
Evidence: Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗ · Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗
Is the crown-of-thorns starfish venomous?
Yes, the spines of the crown-of-thorns starfish are sharp and venomous. A 2023 study in PeerJ says the venom contains saponins and plancitoxin proteins. A spine wound can cause nausea, numbness, vomiting, joint aches and sometimes paralysis. Mongabay Indonesia reports that spine wounds are very painful, can swell for hours or days and may bring on fever. The PeerJ study also notes one documented human death: a woman who died of anaphylactic shock 13 hours after being stung. If you are pricked by its spines, seek medical care at a health facility immediately.
Evidence: PeerJ (2023, via PMC) — Crown-of-thorns starfish spines secrete defence proteins ↗ · Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗
What should you do if you find a crown-of-thorns starfish?
Do not touch, hold or step on a crown-of-thorns starfish, and keep your distance when swimming or diving. Do not try to kill them yourself. Report large numbers to the local protected-area authority, such as the national park office. In the Togean Islands, clean-ups have been run with the Togean Islands National Park office, resort operators and visitors. In 2019, about 8,000 starfish measuring 8–48 cm across were removed from the park with bamboo tongs and collected on boats to avoid direct contact. In the long term, fisheries management and less nutrient runoff from land help prevent outbreaks.
Evidence: Mongabay Indonesia (2022) — Catatan Akhir Tahun: Bintang Laut Berduri Bisa Jadi Ancaman Terumbu Karang Indonesia ↗ · Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗ · Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗
Explore related habitats
These habitat relationships are supported by species sources in this guide. This is not a complete range map.
Scientific classification of the Crown-of-thorns starfish
| Kingdom | Animalia |
|---|---|
| Phylum | Echinodermata |
| Class | Asteroidea |
| Order | Valvatida |
| Family | Acanthasteridae |
| Genus | Acanthaster |
| Species | Acanthaster planci |
Source: GBIF Backbone Taxonomy, adjusted to the ranks commonly used in school biology (for example class Reptilia).
Common questions about the crown-of-thorns starfish
What is the scientific name of the crown-of-thorns starfish?
The scientific name of the crown-of-thorns starfish is Acanthaster planci, in the family Acanthasteridae. In Indonesian it is called Bintang laut mahkota duri.
What kind of animal is the crown-of-thorns starfish?
The crown-of-thorns starfish is a marine animal in the family Acanthasteridae. By diet it is a carnivore (meat-eater): a hard-coral polyp eater (corallivore).
Where does the crown-of-thorns starfish live in Indonesia?
In Indonesia, this guide records the crown-of-thorns starfish in: Coral reefs throughout Indonesia, from Aceh to Papua; outbreaks recorded in Sulawesi (e.g. Togean, Sombori) and Kalimantan.
Source-supported habitats: Coral Reefs.
What does the crown-of-thorns starfish eat?
Diet of the crown-of-thorns starfish: living hard corals, especially Acropora. That makes it a carnivore (meat-eater). Source: Animal Diversity Web.
How does the crown-of-thorns starfish reproduce?
The crown-of-thorns starfish reproduces by laying eggs (oviparous). Broadcast spawner: males and females release gametes into the sea, fertilisation happens in the water, and the larvae drift as plankton. Source: Animal Diversity Web.
Is the crown-of-thorns starfish venomous?
Yes. The crown-of-thorns starfish is venomous. Its spines are venomous; stings can cause pain, prolonged vomiting and swelling. Source: Lee et al. 2013, Hemolytic activity of venom from crown-of-thorns starfish Acanthaster planci spines (J Venom Anim Toxins Incl Trop Dis).
Do not catch, handle or disturb wild animals. If bitten, stung or exposed to its toxins, go to the nearest health facility straight away.
Is the crown-of-thorns starfish nocturnal?
The cited source records the crown-of-thorns starfish as nocturnal (active at night). Large individuals and outbreak populations may also feed by day. Source: Ling et al. 2020, Homing behaviour by destructive crown-of-thorns starfish is triggered by local availability of coral prey, Proceedings of the Royal Society B (abstract via Europe PMC).
See also the list of nocturnal and diurnal animals in Indonesia.
What are the main features of the crown-of-thorns starfish?
Key features of the crown-of-thorns starfish, from this guide’s sources: Key feature: large, many-armed body covered in long, sharp venomous spines; Body diameter: Usually 28–41 cm across depending on locality; individuals over 60 cm have been recorded.
How big is the crown-of-thorns starfish?
Body diameter: Usually 28–41 cm across depending on locality; individuals over 60 cm have been recorded. Source: Marine Biology — Uthicke et al. (2024), The crown-of-thorns seastar species complex.
Is the crown-of-thorns starfish dangerous to people?
Venomous spine wounds: pain, swelling, nausea and vomiting.
Do not approach, catch or handle wild animals. If you are injured or bitten, get medical care at a health facility straight away.
What is the scientific classification of the crown-of-thorns starfish?
Scientific classification of the crown-of-thorns starfish: kingdom Animalia, phylum Echinodermata, class Asteroidea, order Valvatida, family Acanthasteridae, genus Acanthaster, species Acanthaster planci.
Source: GBIF Backbone Taxonomy, adjusted to the ranks commonly used in school biology.
Sources & references
- Marine Biology (Uthicke et al. 2024, via VLIZ) — The crown-of-thorns seastar species complex: knowledge on the biology and ecology of five corallivorous Acanthaster species ↗
- WoRMS — Acanthaster solaris (Schreber, 1793) ↗
- PeerJ (2023, via PMC) — Crown-of-thorns starfish spines secrete defence proteins ↗
- Mongabay Indonesia (2022) — Bintang Laut Berduri Ini Jadi Musuh Terumbu Karang ↗
- Mongabay Indonesia (2022) — Catatan Akhir Tahun: Bintang Laut Berduri Bisa Jadi Ancaman Terumbu Karang Indonesia ↗
- Biodiversitas (2024) — Analysis of environmental parameters supporting the abundance of Acanthaster planci in the Wakatobi and Sombori Marine Protected Areas, Sulawesi, Indonesia ↗
- Animal Diversity Web ↗
- Ling et al. 2020, Homing behaviour by destructive crown-of-thorns starfish is triggered by local availability of coral prey, Proceedings of the Royal Society B (abstract via Europe PMC) ↗
- Lee et al. 2013, Hemolytic activity of venom from crown-of-thorns starfish Acanthaster planci spines (J Venom Anim Toxins Incl Trop Dis) ↗
- GBIF Backbone Taxonomy (GBIF) ↗
References can change. Check dates and context in the original source. How we use sources and data →
Cite this page
Credit PanduanHewan when referring to this page. Check the original evidence sources before reusing a claim.
PanduanHewan. Crown-of-thorns starfish (Acanthaster planci). Last substantive update: 1 October 2026. https://panduanhewan.org/en/species/crown-of-thorns-starfish/