Description & Behavior
Twoband anemonefishes, Amphiprion bicinctus (Rüppell, 1830), often called a clownfish or threebanded anemonefish, are the most common clownfish in the Red Sea. They are found at depths from 1-30 m.
Dorsal spines: 9-10; Dorsal soft rays: 15-17; Anal spines: 2-2; Anal soft rays: 13-14.
Twoband anemonefish are yellow-orange with 2 black-edged white bands, the first running just behind the head, the second from the notch between the spinous and soft dorsal fin to the abdomen. Max size: 14 cm total length (male/unsexed). This species has been reared in captivity.
World Range & Habitat
The twoband anemonefish inhabits lagoons and outer reefs and live symbiotically with anemones such as Entacmaea quadricolor, Heteractis aurora and Stichodactyla gigantea. Western Indian Ocean: Red Sea and Chagos Archipelago. Reef-associated; non-migratory; marine. Climate: tropical; 31°N-7°S.
This species is well known for its relationship with anemones, a classic example of symbiosis. The tentacles of the anemone protect the clownfish from predators. When the clownfish first contacts the anemone, it jerks back from the stinging nematocysts, but gradually its mucus coating gives it immunity. The anemone benefits by the clownfishes movement among its tentacles, which increases water flow and therefore oxygen. The anemone may also feed on the fish’s waste material.
Some clownfish live in anemones as juveniles and move to corals as adults. Some never move from their anemones. Some are territorial and will dart meters out and “attack” depth gauges, mouthpieces or divers themselves.
Clownfish in aquariums have been observed bathing in air bubbles, a behavior similar to the clownfish’s behavior within the tentacles of the anemone.
Feeding Behavior (Ecology)
The twoband anemonefish feeds on benthic (bottom-dwelling) algae and occasionally on zooplankton.
Clownfish can change from male into female. A fascinating characteristic of clownfish is that they begin their lives as males, but when a female dies the dominant male will change into a female. A non-dominant male will then become the dominant male (called protandry).
Fertilization is external. They are known as guarders, nesters. Sex reversal is completed between 26-145 days. In a field test, a functional male laid eggs in 26 days after removal of the female. Eggs are laid at the base of the anemone, and the parent often rubs the anemone causing the tentacle to extend, which in turn forms a protective canopy for the eggs of the fish.
Conservation Status & Comments
Not yet on the IUCN Red List of Threatened Species. Harmless to humans.
References & Further Research
Coral Reef Fishes, Indo-Pacific and Caribbean, by Ewald Lieske and Robert Myers, Harper Collins
Jacques Cousteau: The Ocean World, Abradale Press.
Research Amphiprion bicinctus @
Barcode of Life BioOne Biodiversity Heritage Library CITES Cornell Macaulay Library Encyclopedia of Life (EOL) ESA Online Journals FishBase Florida Museum of Natural History Ichthyology Department GBIF Google Scholar ITIS IUCN RedList (Threatened Status) Marine Species Identification Portal NCBI (PubMed, GenBank, etc.) Ocean Biogeographic Information System PLOS SIRIS Tree of Life Web Project UNEP-WCMC Species Database WoRMS