Fish guide

Ocellaris Clownfish

Amphiprion ocellaris

A small, hardy anemonefish and one of the most recognizable marine aquarium species. Captive-bred Ocellaris Clownfish are widely available, adapt readily to aquarium life, and usually accept prepared foods.

Quick Reference

Care difficulty
Very easy for a marine fish
Adult size
3-4.3 inches (7.5-11 cm); females are larger
Lifespan
Typically 6-10 years; potentially 10-20+ years with excellent care
Minimum tank
20 gallons for one fish or a compatible pair
Temperature
74-80°F (23-27°C)
Salinity
1.023-1.026 specific gravity (about 32-35 ppt)
pH
8.1-8.4
Temperament
Peaceful to semi-aggressive; more territorial after pairing or spawning
Diet
Omnivore
Social requirement
Singly or as a compatible pair
Reef safe
Yes
Beginner-friendly
Yes

Key Takeaways

  • Difficulty: A host anemone is not required in captivity.
  • Minimum tank size: Use a fully cycled, stable marine aquarium and quarantine when possible.
  • Reef safe: A mature pair may become territorial around its chosen area.

Natural habitat

Ocellaris Clownfish occur in the eastern Indian Ocean and western Pacific Ocean, including the Andaman Sea, Indonesia, the Philippines, Southeast Asia, the Ryukyu Islands, and northwestern Australia.

They live in shallow protected lagoons, coastal reefs, and outer reef slopes associated with host anemones. Natural water movement is generally low to moderate around sheltered lagoons and reef margins.

Aquarium setup and parameters

Provide stable live rock or reef-safe structure with caves, visual barriers, a modest open area, and low to moderate flow without a constant high-velocity jet. A standard 20-gallon-long footprint or larger provides useful territory and more stable water volume.

An anemone is optional and should only be added to an appropriately mature, well-lit aquarium that meets that anemone species' needs. Keep temperature at 74-80°F (23-27°C), specific gravity at 1.023-1.026 (about 32-35 ppt), pH at 8.1-8.4, and ammonia and nitrite at 0 ppm.

Behavior, pairing, and tank mates

Ocellaris Clownfish are active and curious but usually site-attached. A mature female or breeding pair may chase fish that approach its territory. Keep one fish or one compatible pair; groups can become unstable in small aquariums.

Peaceful gobies, blennies, firefish, cardinalfish, royal grammas, small wrasses, chromis, and other nonpredatory community reef fish can be suitable. Avoid large predators, highly aggressive species, and additional clownfish species or unrelated pairs in small to medium aquariums.

Diet and feeding

Feed a varied omnivorous marine diet based on quality pellets or flakes, supplemented with frozen and fresh marine foods. Marine pellets, quality flakes, mysis shrimp, enriched brine shrimp, copepods, finely chopped krill or seafood, and foods containing marine algae or spirulina are supplied examples.

Offer small portions once or twice daily. Juveniles and conditioning breeding pairs may benefit from two or three smaller feedings.

Breeding and health

All juveniles begin sexually immature. Within a social pair or group, the largest dominant fish becomes female and the next-largest becomes the breeding male. Adults often spawn readily, but raising larvae requires live foods and dedicated equipment.

Common health concerns include marine ich, velvet, Brooklynella, bacterial infections, flukes, poor water quality, and injury. Quarantine new fish in a separate, cycled observation or treatment system when possible; do not medicate the display reef or expose invertebrates to copper.

Frequently Asked Questions

Does an Ocellaris Clownfish need an anemone?

No. Ocellaris Clownfish live normally without an anemone in captivity and often adopt a cave, coral, or another sheltered area. Add an anemone only if the aquarium is mature and can meet that species' lighting, flow, space, and water-quality requirements.

Sources and Further Reading

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