What Do Crown Of Thorns Starfish Eat

 What Do Crown Of Thorns Starfish Eat


What Do Crown Of Thorns Starfish Eat: The Crown of Thorns Starfish (Acanthaster planci) is a marine creature that has garnered significant attention and concern due to its impact on coral reefs. These remarkable echinoderms are native to the Indo-Pacific region and are characterized by their striking appearance, featuring numerous long, venomous spines on their bodies. However, it is not their appearance but their feeding habits that have made them infamous in the world of marine biology.

Crown of Thorns Starfish are predominantly herbivorous, with a diet primarily composed of coral polyps. Coral polyps are tiny, soft-bodied organisms that build the calcium carbonate skeletons that form the intricate structures of coral reefs. This makes the Crown of Thorns Starfish a major threat to coral ecosystems. They use their flexible arms to climb onto coral colonies, and their tube feet to grasp and manipulate coral polyps.  

The Crown of Thorns Starfish’s insatiable appetite can have devastating consequences for coral reefs. When populations of these starfish surge, they can quickly decimate vast stretches of coral, leading to reef degradation and loss of crucial marine biodiversity. As such, understanding their feeding habits is essential for conservation efforts aimed at preserving the health and vitality of coral ecosystems.

What Do Crown Of Thorns Starfish Eat

What eats crown of thorns sea star?

Predators of adult crown-of-thorns starfish include the giant triton snail, the humphead Maori wrasse, starry pu erfish and titan trigger fish. Predators of juvenile starfish include shrimp, crabs and polychaete worms.

The Crown of Thorns Starfish (Acanthaster planci) faces predation from a variety of natural predators within its native Indo-Pacific habitat. Some of the main creatures that feed on Crown of Thorns Starfish include:

Triton’s Trumpet Snails (Charonia tritonis): These large predatory snails are known to be significant natural predators of Crown of Thorns Starfish. They can use their long, extendable proboscis to pierce the starfish and inject a paralyzing toxin before consuming them.

Giant Triton Snails (Tritonidae family): Like Triton’s Trumpet Snails, giant Triton snails are known to feed on Crown of Thorns Starfish. They are especially effective in controlling the starfish populations on coral reefs.

Certain species of Pufferfish: Some species of pufferfish are known to consume Crown of Thorns Starfish as part of their diet. The toxins present in the starfish don’t seem to affect these pufferfish.

Hawksbill Sea Turtles (Eretmochelys imbricata): These turtles occasionally consume Crown of Thorns Starfish, especially when other food sources are scarce.

Some reef-dwelling fish: Certain fish species, like the Harlequin Filefish (Oxymonacanthus longirostris), have been observed feeding on juvenile Crown of Thorns Starfish.

It’s important to note that while these predators play a role in controlling Crown of Thorns Starfish populations in their natural habitat, factors like overfishing, habitat destruction, and human-induced disturbances have disrupted the balance of these ecosystems, contributing to outbreaks of Crown of Thorns Starfish that can harm coral reefs.  

Can humans eat crown-of-thorns starfish?

However, certain species are highly poisonous and dangerous for consumption, such as the crown-of-thorn starfish.

Crown-of-Thorns Starfish (Acanthaster planci) are not typically consumed by humans for several reasons. First and foremost, these marine creatures are known to be venomous. They have long, sharp spines covered in a toxic substance that can cause severe pain, swelling, and even allergic reactions if they come into contact with human skin.  

Secondly, even if the spines were removed, Crown-of-Thorns Starfish are not considered a desirable source of food due to their unpalatable taste and texture. They are primarily herbivorous, feeding on coral polyps, which likely gives them an unappealing flavor.

Additionally, there is no significant cultural or culinary tradition of consuming Crown-of-Thorns Starfish, unlike other types of seafood such as fish, shrimp, or crabs. As a result, there is little to no market demand for them as a food source.

While there have been some experimental efforts to convert Crown-of-Thorns Starfish into seafood products, these attempts have not gained widespread acceptance or popularity, mainly due to the aforementioned reasons of toxicity and unappealing taste.

How much coral do crown-of-thorns starfish eat a day?

Crown-of-thorns starfish are a major predator of coral. An adult crown-of-thorns starfish can consume up to 478 square centimetres (about the size of a dinner plate) of coral each day.

The amount of coral consumed by Crown-of-Thorns Starfish (Acanthaster planci) on a daily basis can vary widely depending on several factors, including the size and age of the starfish, the availability of coral, and environmental conditions. On average, an adult Crown-of-Thorns Starfish can eat a significant amount of coral, often ranging from 6 to 12 square meters (65 to 130 square feet) of coral reef per year. When you break this down into daily consumption, it equates to approximately 0.02 to 0.04 square meters (0.2 to 0.4 square feet) of coral reef per day.

However, during population outbreaks, when large numbers of these starfish converge on a coral reef, the collective impact can be devastating. During such outbreaks, individual starfish may eat even more coral, and they can quickly strip vast areas of reef of their living coral cover.

It’s important to note that Crown-of-Thorns Starfish are opportunistic feeders, and their consumption rates can fluctuate depending on factors like food availability and the health of the coral reef. Their feeding habits can be a significant concern for coral reef conservation efforts, as outbreaks can lead to widespread damage and coral mortality, contributing to the degradation of these vital marine ecosystems.

What kills crown-of-thorns starfish?

Divers inject the starfish with either vinegar or bile salt solution, and leave them in place on the reef. These controls techniques kill quickly and effectively. Within 24 hours there’s basically nothing left of the starfish, who go into an autoimmune self-destructive process.

Controlling and killing Crown-of-Thorns Starfish (Acanthaster planci) populations is essential for protecting coral reefs, as these starfish can be destructive to coral ecosystems. Several methods and natural predators are employed to manage and reduce their numbers:

  • Manual Removal: Divers and marine conservationists often physically remove Crown-of-Thorns Starfish from coral reefs. They use specialized tools to cut the starfish into pieces, as even a small piece can regenerate into a new starfish if left intact.
  • Predators: Certain marine creatures prey on Crown-of-Thorns Starfish. Triton’s Trumpet Snails and giant Triton snails are natural predators that can help control starfish populations.
  • Injectable Toxins: In some cases, divers inject a solution of sodium bisulfate or other chemicals directly into the starfish to kill them. This method is labor-intensive but effective.
  • Biological Control: Research is ongoing into the use of biocontrol methods, such as breeding and introducing native predators or parasites that specifically target Crown-of-Thorns Starfish.
  • Environmental Stress: Reducing stressors on coral reefs, such as overfishing and pollution, can help maintain a balanced ecosystem, making it harder for Crown-of-Thorns Starfish populations to explode.
  • Research and Monitoring: Regular monitoring of coral reefs and early detection of Crown-of-Thorns Starfish outbreaks can enable rapid response and control efforts.

Crown-of-Thorns Starfish management with care and consideration for the overall health of coral reefs, as well as the potential impacts on other marine life. A combination of strategies is often used to minimize the negative effects of these starfish on coral ecosystems.

Why are crown-of-thorns starfish a problem?

Why do we manage crown-of-thorns starfish in the Marine Park? Crown-of-thorns starfish outbreaks cause significant damage to coral reefs across large spatial scales, and are one of the major causes of coral decline across the Great Barrier Reef over the past 40 years.

Crown-of-Thorns Starfish (Acanthaster planci) are a significant problem for several reasons, particularly for coral reef ecosystems:

  • Coral Predation: The primary issue with Crown-of-Thorns Starfish is their voracious appetite for coral polyps. They use their tube feet and acidic stomachs to consume living coral, leaving behind the white, dead skeletons. When their populations surge, as can happen during outbreaks, they can rapidly strip large areas of coral reefs, causing extensive damage and degradation.
  • Biodiversity Loss: The destruction of coral reefs by Crown-of-Thorns Starfish leads to a loss of vital habitat for countless marine species. Coral reefs are among the most biodiverse ecosystems on Earth, and their decline affects the entire food web, from small fish to apex predators.
  • Economic Impact: Coral reefs play a crucial role in supporting fisheries and tourism industries, contributing significantly to local economies. When Crown-of-Thorns Starfish damage reefs, it can lead to economic losses for communities reliant on these industries.
  • Coral Reef Health: Healthy coral reefs are essential for coastal protection, as they act as natural barriers against storms and wave erosion. Weakened reefs are less effective in providing these vital services, making coastal communities more vulnerable to natural disasters.
  • Ecosystem Imbalance: Outbreaks of Crown-of-Thorns Starfish are often associated with environmental stressors, such as overfishing and pollution, which can upset the natural balance of coral reef ecosystems. This makes it even harder for reefs to recover from starfish predation.

The Crown-of-Thorns Starfish poses a significant threat to the health and resilience of coral reefs, leading to ecological, economic, and environmental problems. Managing and mitigating the impact of these starfish is crucial for the preservation of these invaluable marine ecosystems.

Do crown-of-thorns starfish eat sponges?

Crown-of-Thorns prefer to feed on branching or table corals like Acorpora sp. but will also feed on Porites or Motipora corals, and have been documented feeding on sponges, soft corals, and encrusting organisms like algae.

Crown-of-Thorns Starfish (Acanthaster planci) do consume sponges as part of their varied diet. While their primary source of nutrition is coral polyps, they are opportunistic feeders, and their diet can include other organisms found on coral reefs, including sponges.

Sponges are filter-feeding animals that attach themselves to the substrate of coral reefs. They play a crucial ecological role by filtering water and providing habitat for various marine species. When Crown-of-Thorns Starfish populations surge, they can deplete coral resources and turn to sponges as an alternative food source.

This behavior is particularly concerning because it can lead to further damage to coral reef ecosystems. Not only do Crown-of-Thorns Starfish consume the living coral that forms the foundation of the reef, but they can also impact the sponge communities, disrupting the balance of species on the reef.

Efforts to control Crown-of-Thorns Starfish outbreaks often focus on reducing their numbers and preventing widespread coral and sponge destruction. Monitoring and managing these outbreaks are essential for the overall health and sustainability of coral reef ecosystems, as both corals and sponges are critical components of these diverse and fragile environments.

Do crown-of-thorns starfish eat other things besides coral?

While coral is their primary food source, they have been known to consume sponges, algae, and other small invertebrates in the absence of coral.

Crown-of-Thorns Starfish (Acanthaster planci) are primarily herbivorous, with coral polyps as their preferred and primary food source. However, they are opportunistic feeders, which means they can consume other organisms besides coral when coral is scarce or unavailable. Some of the additional items they may eat include:

  • Sponges: When coral is limited or during specific stages of their life cycle, Crown-of-Thorns Starfish have been observed feeding on sponges. This behavior can have implications for sponge populations on coral reefs.
  • Algae: These starfish may consume different types of algae, including macroalgae and microalgae, although they do so less frequently than they feed on coral.
  • Detritus: In some instances, they may scavenge organic matter and detritus present on the reef substrate.

They prefer coral polyps and tend to have the most significant impact on coral reef ecosystems when their populations surge and they primarily target corals. When outbreaks occur, the starfish can strip large areas of living coral, leading to significant reef degradation and a decline in biodiversity. Managing and controlling these outbreaks is critical for preserving the health and resilience of coral reefs.

What is the crown-of-thorns starfish, and why is it significant?

The Crown-of-Thorns Starfish (Acanthaster planci) is a large and striking marine species native to the coral reefs of the Indo-Pacific region. It’s named for the sharp, venomous spines that adorn its upper surface, resembling a crown. While individually captivating in appearance, these starfish are significant for several reasons:

  • Feeding Behavior: Crown-of-Thorns Starfish are primarily herbivorous and have a voracious appetite for coral polyps. They use their flexible arms to grasp coral colonies and then extrude their stomachs over the coral to digest and consume the living tissue. This feeding behavior can lead to significant damage to coral reefs.
  • Outbreaks: Periodic outbreaks of Crown-of-Thorns Starfish can occur, where their populations surge, and they become a major threat to coral ecosystems. During outbreaks, they can rapidly strip large areas of coral, causing coral mortality and reef degradation.
  • Ecosystem Impact: The impact of these starfish on coral reefs extends beyond coral mortality. The loss of coral reef habitat due to their predation affects the entire marine ecosystem, from fish populations to coastal protection and tourism.
  • Conservation Concern: The management and control of Crown-of-Thorns Starfish outbreaks are crucial for the preservation of coral reefs, which are not only biodiverse but also provide important ecosystem services to humans.
  • Scientific Research: Studying these starfish and their interactions with coral reefs contributes to our understanding of marine ecology and can inform conservation strategies.

The Crown-of-Thorns Starfish is significant due to its destructive feeding behavior, its ability to trigger coral reef degradation, and the importance of managing its populations to safeguard these critical marine ecosystems.

What Do Crown Of Thorns Starfish Eat


The dietary habits of the Crown of Thorns Starfish, primarily centered around consuming coral polyps, have profound implications for the delicate balance of marine ecosystems. These starfish are natural components of coral reef environments, but when their populations spiral out of control, they become formidable threats to the very ecosystems they inhabit.

Efforts to mitigate the impact of Crown of Thorns Starfish often involve targeted removal or culling programs, which aim to reduce their numbers and protect vulnerable coral reefs. Additionally, research into the ecological factors that trigger population outbreaks is crucial for developing proactive measures to prevent their destructive surges.

Understanding what Crown of Thorns Starfish eat is just one facet of the larger challenge of coral reef conservation. These vibrant and biodiverse habitats face numerous threats, including climate change, ocean acidification, pollution, and overfishing. Addressing these complex issues requires a holistic approach that combines scientific research, conservation initiatives, and global cooperation.

Ultimately, protecting coral reefs and the incredible marine life they support is a responsibility that extends beyond the scientific community. It is a collective endeavor that involves governments, organizations, and individuals alike. Only through concerted efforts can we hope to safeguard these vital ecosystems for future generations, ensuring that the Crown of Thorns Starfish remains a fascinating part of the ocean’s biodiversity rather than a destructive force.

Related post

Leave a Reply

Your email address will not be published. Required fields are marked *