When it comes to saltwater fish, the clownfish is probably one of the most recognized, thanks to its appearance in the Disney film “Finding Nemo.” Also known as anemonefish, clownfish are pretty robust, with serious defenses against predators. Despite this, they’re still pursued by predatory marine creatures.
Predators that eat clownfish include red bass and other piscivores, including sharks, stingrays, and eels. Due to the clownfish’s symbiotic mutualism with sea anemones, however, clownfish often evade predators with ease. They’re most commonly preyed upon when away from their host anemone.
This article dives deep into the different marine animals that prey on clownfish and discusses how these anemonefish protect themselves from predators. Additionally, the article briefly touches on the predation behaviors of clownfish, so stick around.
Animals That Prey on Clownfish
Potential predators of clownfish include nearly any larger fish species that prey on other fish. Animals that primarily eat other fish are called “piscivores,” who often wait patiently, stealthily stalking their prey.
Groupers are one example of piscivores that prey on clownfish and include several fish species, including sea bass. Red bass, in particular, is an aggressive predator that eats clownfish if given the chance.
In addition to predatory fish, clownfish are vulnerable to sharks, stingrays, and eels.
Interestingly, clownfish do not have many predators despite their relatively small size. This is due to their symbiotic mutualistic relationship with sea anemones, which we’ll discuss more in-depth later. Without the presence of the sea anemone, clownfish would be far more vulnerable.
In fact, most clownfish are preyed on when away from their host anemone.
Contrary to popular belief that likely came from the Disney movie “Finding Nemo,” barracudas do not regularly prey upon clownfish or their eggs.
Are Humans a Threat to Clownfish?
Humans are a significant threat to clownfish. While humans do not capture clownfish for consumption, the species is highly sought after for use in saltwater aquariums. Today, clownfish make up close to half of the saltwater aquarium fish trade, with ¾ of the fish captured from the wild.
The movie “Finding Nemo” dramatically increased the popularity of the fish.
Despite this, clownfish are not listed as threatened or endangered. The experts cite aquaculture facilities as a factor in reducing wild captures of the species. However, clownfish populations continue to decline in certain parts of the world due to the exploitation of the fish.
In addition to overfishing, climate change poses a significant threat to clownfish populations.
Ocean acidification negatively affects the species, resulting in a loss of smell and impaired hearing. This also adversely affects the sea anemones in Australia, which clownfish rely on for protection.
How Do Clownfish Protect Themselves?
Clownfish protect themselves against predators by living in sea anemones, protected by the anemone’s stinging tentacles. Male clownfish protect their eggs by standing guard against predators.
Additionally, clownfish swim in schools and defend host anemones in groups, increasing their chances of survival. Sea anemones possess nematocysts on their tentacles that help them capture small prey to eat.
These stinging tentacles can injure or kill other marine animals that come too close.
Clownfish, however, have developed an immunity to the anemone’s stings. The clownfish coats itself with mucus, which protects itself from the nematocysts. The mucus also acts as a form of communication to help the anemone “recognize” the clownfish as harmless.
Scientists aren’t sure where the mucus comes from, but they know that clownfish develop it after acclimating to the sea anemone’s sting. They brush against the anemone, getting stung several times, eventually forming the layer of protective mucus.
As such, clownfish live peacefully in sea anemones, benefiting from their protection.
The symbiotic mutualism protects the clownfish and the sea anemone. Clownfish are highly territorial and aggressive, as they’ll quickly pursue other fish, chasing them off if they attempt to eat the anemone’s tentacles.
Clownfish also keep sea anemones clean by consuming any food particles left behind after the anemone feeds. Some forms of protective cooperation among clownfish include swimming in schools and joint defense of shelter.
These defenses help increase their survival chances.
Protection of Clownfish Eggs
Clownfish are protandrous hermaphrodites, meaning they’re all born male, and the largest fish becomes female. If a female dies, the process continues, with the largest male transforming into a female fish.
Because clownfish live in warm, tropical waters, they spawn year-round.
Males and females form monogamous bonds, with the male preparing the nest prior to spawning. The nest is critical to the survival of the clownfish eggs, and male clownfish prepare it under the host anemone’s stinging tentacles for protection.
Males externally fertilize eggs once laid by the female. From there, males regularly protect the nest from predators, incubate the eggs, and remain on guard.
The male periodically cleans debris from the nest to keep it well-oxygenated.
The eggs hatch into larvae that float to the bottom of the ocean. Shortly thereafter, the 3 mm (.12-inch) larvae use phototaxis to swim to the surface of the water. There, the juvenile clownfish spend a week living among plankton, receiving nutrition from copepods, phytoplankton, and brine shrimp.
Around 8 to 12 days after hatching, clownfish once again settle to the bottom of the ocean, searching for a host sea anemone to begin the acclimation process, beginning the life cycle again.
Are Clownfish Predators?
Clownfish are predators, including both adults and juveniles. They are planktivores, meaning they consume various types of plankton. Juvenile clownfish consume copepods, brine shrimp, and phytoplankton.
Copepods, in particular, are a common food source for juvenile clownfish. These highly evasive crustaceans have a robust escape response, but despite the juvenile clownfish’s immature jaws, muscles, and fins, they capture this prey with ease.
The stealthy juveniles move within 1 mm (.04 inch) of the copepod and launch their attack.
As the clownfish grow older, their speed increases. The success of capture depends on the stealth of the clownfish. If a copepod initiates an escape response, the clownfish’s capture success decreases dramatically.
Despite having multiple predators, clownfish are pretty well-adapted to holding their own, thanks to the relationship they share with sea anemones and their strong parental care for their young.
They’re most vulnerable when they’re away from their host, but even then, they utilize protective cooperation to increase their chances of survival. In fact, the biggest threat to clownfish seems to be humans and climate change, as the oceans continue to acidify, harming coral reefs which anemonefish rely on for protection.
- American Oceans: A Guide To The Different Types of Groupers
- Fishing World: Fish Facts – Red Bass
- Marine Sanctuary: Sea Wonder – Spotted Eagle Ray
- Kylon Powell: What Do Moray Eels Eat?
- National Geographic: Breeding Aquarium Fish Can Help Save Reefs
- Federal Register: Findings on a Petition To List the Orange Clownfish as Threatened or Endangered Under the Endangered Species Act
- Royal Society: Ocean Acidification Affects Clownfish Hearing
- Flinders University: Climate Change an Anemone Enemy
- U.S. Geological Survey: Predation Strategies of Larval Clownfish
- U.S. Geological Survey – Nonindigenous Aquatic Species: Clown Anemonefish
- Augsburg College: Clownfish (Also Called Anemonefish)
- Ocean Planet – Popular Science: Immunity, Mimicry, and Protection
- Augsburg College: Coral Reef Aquarium
- National Oceanic and Atmospheric Administration – Gray’s Reef: Reef Fish Behavior
- University of Florida – Florida Museum: Amphiprion percula
- University of Michigan – Animal Diversity Web: Amphiprion frenatus