The Ocellaris Clownfish, Amphiprion ocellaris, also called the False Percula Clownfish and Clown Anemonefish, has always been one of the most popular saltwater aquarium fish but was popularized in the 2003 Disney movie Finding Nemo, as the main character, Nemo, is an Ocellaris Clownfish.
The Ocellaris Clownfish can be distinguished from its close relative, The True Percula Clownfish Amphiprion percula, by its coloration. The True Percula Clownfish tends to have a thicker black border around the white stripes, and a deeper orange color on its body. They also differ in the number of dorsal spines; True Percula Clownfish have eleven while Ocellaris Clownfish have ten.
Ocellaris Clownfish share a mutual commensal relationship with anemones Stichodactyla gigantea, S. mertensii, and Heteractis magnifica. They may host in other anemones such as the Bubble Tip Anemone Entacmaea quadricolor in captivity. Clownfish should not be kept in the same aquarium as anemones that are toxic or fish-eating anemones such as, but not limited to, Actinodendron spp. Hell’s Fire anemones, Condylactis spp., and Pseudocorynactis spp. Not much is known about exactly how Clownfish are immune to the stings of their host anemones, but it is known that the clownfish “slime coat,” a coating of mucous used by all fish to prevent parasitic and bacterial infections, is much thicker than the slime coat of other fish and is specially adapted to not trigger the firing of its hosts anemone’s nematocysts. Both the clownfish and the anemone benefit from their relationship. The anemone protects the clownfish from predators, while the clownfish helps to feed and clean the anemone. The clownfish even lay their eggs at the base of the anemone, protecting them from would-be predators.
It is a common misconception that captive bred clownfish will not host in anemones. In fact many captive bred clownfish adopt unnatural hosts such as Euphyllia, Ricordea, and Xenia corals. One way to help encourage your new captive bred clownfish to host in an anemone is to select one of the species they naturally associate with in the wild. Another way is to quarantine your new clownfish in a relatively smaller tank full of the species of anemone you want it to host in. The more contact the clownfish has with the anemones, the more likely it will be to adopt one.
Amphiprion ocellaris was first ornamental marine fish species to be successfully bred in captivity. Captive Bred Clownfish are much more hardy than their wild-caught cousins and have a smaller impact on the environment. Many beautiful color variations such as ORA® Black Ice Semi-Snowflake, ORA® Midnight, ORA® Domino, ORA® Naked, ORA® Snowflake, Sanjay’s Black Photon hybrid, and Misbar Ocellaris Clownfish have been produced in captivity, but many people prefer the natural, wild coloration which is still readily available as captive bred. Wild-caught Clownfish are only recommended for expert Clownfish keepers and breeders, because they are much less hardy and have high mortality rates due to improper handling during collection, Clownfish Disease Brooklynella, and internal parasites.
Ocellaris Clownfish, particularly captive bred specimens, are less aggressive than other clownfish species, but care must be taken when pairing Ocellaris Clownfish. Only one male/female pair may be kept in an aquarium, as the female clownfish is very territorial. When choosing a mate for an older clownfish, choose a small, but healthy clownfish. After quarantining the new clownfish, capture the older clownfish and put it in a basket or behind a divider so that it can see, but not harm the new clownfish. Let the new clownfish explore the aquarium and get used to its surroundings before letting the older clownfish out of its enclosure. It’s normal for the female or dominant clownfish to rush at the new clownfish, which should show submission by turning sideways and vibrating. At first the more dominant clownfish may tear the fins of the smaller clownfish, so be vigilant. If the fighting escalates and the smaller clownfish is in danger, put the dominant clownfish back into her enclosure and try reintroducing them when the smaller clownfish regains its strength.
Ocellaris Clownfish are protandrous hermaphrodites; the males can change sex to become females, but not vice versa. Clownfish are hatched without gender as sexually immature juveniles. If the dominant female of the pair dies, the male will change into a female, and the most dominant juvenile clownfish in the group will change into a male. If a juvenile changes into a male, it can not change back. A female clownfish can not change back into a male, even if a larger, more aggressive female is introduced. The less dominant female will be driven out or killed.
Captive bred Ocellaris Clownfish are easy to keep. A pair can be kept in a 20 gallon or larger aquarium and will usually accept a wide variety of frozen, pellet, and flake foods. Ocellaris Clownfish are omnivores and should be provided a varied diet of frozen meaty foods, seaweed sheets, and prepared omnivore diets. Since Clownfish are aggressive toward each other and similar species, avoid keeping the peaceful Ocellaris Clownfish with other Clownfish species or Damselfish. Do not house them with large, aggressive fish like triggerfish or puffers.
by Felicia McCaulley
Photos by Greg Rothschild
ORA® Tank Bred Naked Ocellaris Clownfish