What Do Clownfish Eat? Everything You Need to Know

Clownfish (Amphiprion ocellaris) are small, vibrant tropical fish renowned for their symbiotic relationship with sea anemones. They have bright orange, red, and black bodies with three white vertical bars. Clownfish inhabit warm coral reefs in the Indian and Pacific Oceans and are ideal beginner saltwater aquarium fish. Clownfish have different diets depending on whether they are wild or captive. Continue reading to discover everything you need to know about what clownfish eat.

What Foods Do Clownfish Eat?

In the wild, clownfish are omnivores that eat zooplankton, phytoplankton, algae, and a variety of other foods.

The main foods that wild clownfish eat include:

• Mysis shrimp
• Brine shrimp
• Zooplankton
• Phytoplankton
• Algae
• Krill
• Smelt
• Black worms
• Copepods
• White worms (Enchytraeus albidus)
• Various leftover foods from the sea anemone.

The majority of a clownfish’s diet consists of zooplankton and algae. However, clownfish and sea anemones share a mutualistic, symbiotic relationship in which each species provides the other with critical survival benefits. The sea anemone’s leftover food serves as a supplementary, yet consistent, food source for the clownfish.

When the sea anemone is finished eating something it has killed and captured, the clownfish will often eat what’s left. The clownfish helps the sea anemone by depositing fecal matter that provides beneficial nutrients to its host.

Clownfish are protected from deadly anemone stings by a specialized, thick mucus coating, which prevents the triggering of the anemone’s nematocysts. This mucus allows the fish to live within the tentacles for protection while providing the anemone with cleaning and nutrients.

What Do Clownfish Eat in Captivity?

Clownfish are one of the most popular, hardy, and beginner-friendly marine aquarium fish, due to their colorful appearance and engaging behavior. They adapt well to captivity, often thriving without a host anemone. Captive clownfish eat formulated foods like pellets, flakes, frozen brine or Mysis shrimp, and other frozen meaty foods, usually fed 1–2 times daily.

When they are placed in aquariums, clownfish lose access to the foods that they commonly eat in the ocean. In captivity, these nutrients are replaced by:

• Mysis
• Krill
• Smelt
• Brine
• Frozen worms
• Squid pieces
• Mussels in small amounts
• Prepared fish food
• Spinach
• Nori.

The aquarium trade has contributed to localized declines in wild clownfish populations, as many are still collected from the wild for aquariums.

How Do Clownfish Find Food in the Wild?

Clownfish find their food in the wild using several methods, depending on what they’re trying to eat. Thanks to their symbiotic relationship with sea anemones, clownfish will sit amongst the tentacles of the host and wait for something tasty to float by.

Sometimes, a small shrimp will float by that they can eat on their own; other times, they wait for the sea anemone to kill prey and then eat the leftovers.

Clownfish rarely venture far from the sea anemone. However, they will sometimes leave to forage on the surface of a nearby reef, where they look for plankton and algae.

What Predators Eat Clownfish?

Clownfish have very few ways of protecting themselves since they are neither fast swimmers nor capable of fending off predators. In fact, their best means of protection comes from the sea anemone. Some predators learn a painful or deadly lesson by charging into the sea anemone in pursuit of a clownfish, but this is a rare occurrence.

When clownfish leave the safety of their host sea anemone, predators may strike, swooping in for a quick meal or capturing them to be sold.

These are the most frequent predators of clownfish:

• Barracudas
• Great white sharks
• Eels
• Humans.

Barracudas are fast swimmers and have long snouts that can snatch up clownfish with ease, but it’s humans that clownfish need to worry about most. Large numbers of clownfish are collected from the wild each year for the aquarium trade, making up a significant portion of marine fish imports.

Unfortunately, climate change and coral reef degradation, especially marine heatwaves and bleaching, are major threats to clownfish populations, reducing their numbers in affected regions.