About Amphiprion ocellaris Cuvier, 1830
The common clownfish, Amphiprion ocellaris, is a small fish that reaches a maximum length of 11 cm (4.3 inches). It has a stocky, oval-shaped body that is laterally compressed, with a rounded overall profile. Body color ranges from orange to reddish-brown, though individuals from areas such as Australia’s Northern Territory may be black. The species has three vertical white stripes, each outlined by a fine black line. The first stripe sits directly behind the eye, the second runs through the middle of the body and widens forward into the center of the head, and the third encircles the caudal peduncle. All of the common clownfish’s fins are also outlined with a fine black line. A. ocellaris is frequently mistaken for the closely related Amphiprion percula, which shares the same overall color and pattern at first glance. The two species can be told apart by the thickness of their black outline markings: A. ocellaris also has a taller dorsal fin, and typically has 11 dorsal-fin spines, compared to 10 spines in A. percula. This species is distributed across the Eastern Indian Ocean and western Pacific Ocean, with additional recorded populations in Hawaii (USA, North America), Northern Australia, Southeast Asia, and Japan. Amphiprion ocellaris usually lives in small groups on outer reef slopes or in sheltered lagoons, at a maximum depth of 15 meters. It forms symbiotic relationships with three specific species of sea anemone: Heteractis magnifica, Stichodactyla gigantea, and Stichodactyla mertensii, and only inhabits these anemone species. The reproductive behavior of A. ocellaris matches that of all other anemonefish. It has a monogamous mating system, and both males and females show equal levels of aggression during the spawning process. A reproductive hierarchy based on age and sex exists within A. ocellaris groups. Common clownfish are omnivores that feed on plankton and algae, with their specific diet including algae, copepods, and zooplankton. Feeding access and behavior are shaped by the social hierarchy of A. ocellaris groups. Smaller, less dominant fish face aggression from larger, more dominant group members, leaving them with less energy to forage. These smaller fish also face greater danger when they leave their host anemone due to their small size. As a result, smaller fish generally eat less than dominant fish, and larger fish typically travel farther from the anemone to forage than smaller fish do.
