Amphiprion ocellaris is a
diurnal fish. It is a
protandrous hermaphrodite, which means the male can change its sex to female during its life, and lives in a harem in which an established dominance hierarchy manages the group and keeps individuals at a specific social rank. It is aggressively territorial and is completely dependent on its sea anemone. The presence of the clownfish can be interpreted as a
lure to attract potential anemone's preys close to the
tentacles. And the clownfish can also defend the anemone against some reef fishes which could eat the tentacles.
A. ocellaris form specific social hierarchies within their societies. These social hierarchies result in competition to travel between the different levels of society, which is seen between various ages as well.
Queue selection Queues is the term for social groups of
A. ocellaris. This is because these fish form social hierarchies, or social rank, by outliving the more dominant members of the group. The dominant pair of each queue reproduces more compared to the subordinate fishes. This is the reason for why these individuals should adopt various tactics in which they increase their probability of attaining social dominance. There are two types of
A. ocellaris, settlers and switchers. Settlers prefer shorter queues, while switchers will usually move after settlement. However, studies show that there is no difference in the characteristics between switchers and non-switchers, and there is no data demonstrating that
A. ocellaris utilize the switching tactic for dominance. Although settlement preferences increase the likelihood of gaining social dominance, switching could have the function of increasing social dominance benefits after social dominance has been acquired.
Juvenile Amphiprion ocellaris Juvenile
A. ocellaris have difficulty finding a sea anemone to live in (since they need anemone for survival and shelter). The difficulty also arises in the fact that there exists a hierarchy in each anemone. Thus, when a new juvenile enters an anemone, it begins at the bottom of the social ladder where it is often the victim of aggression by other clownfish. This aggression from other
A. ocellaris in the anemone can cause the juvenile to be chased out of the anemone, and left to search for another anemone.
Group size and patch size Studies have shown that there is a correlation between the size of the group and the size of the patch; however this correlation provides no implication that subordinate group members have less resources. More likely, it is the effects of the patch size on the group member that dominates interactions. An experiment was performed to study the mechanism responsible for the positive correlation between the group size and patch size. The scientists argued that the correlation between the group size and patch size is because of the indirect consequence of the positive relationship between the dominant group member's length and the anemone size. The length of the dominant group member limits the group size because the length of the dominant group member prevents the group of the subordinate group members. This data shows that the patch size and group size correlation does not necessarily imply the decrease in resources of group members subordinate to the dominant group member.
Food habits Amphiprion ocellaris feed on
plankton and
algae, thus they are considered omnivores. Feeding is also affected by the hierarchy in
A. ocellaris groups. Since the smaller, less dominant fish face aggression from the more aggressive fish, they have less energy to forage for food. Thus, they usually do not eat as much as the dominant fish do, because of reduced energy, but also because of the increased danger they face when they leave their anemone since they are smaller. In other words, the larger fish will usually travel farther than the smaller fish. Generally, the
A. ocellaris feed on algae, copepods, and zooplankton.
Reproduction and life history Amphiprion ocellaris have reproductive behaviors very similar to that of all
anemonefish. They have monogamous mating systems, and in their spawning processes, they also have the same levels of aggressiveness between males and females. In addition, there is a reproductive hierarchy that exists between age and sex. are initially male; the largest fish in a group becomes female.
Spawning There is not much data on the reproduction of
A. ocellaris. However, similar behaviors throughout all anemone fishes have been recorded. These fish have
monogamous mating systems, and are territorial of their anemone. Males become more aggressive during
spawning. Male behavior also changes to attract females: biting, chasing, fin extension. Before spawning, the male prepares the nest near the anemone (so that the tentacles of the anemone can protect the nest). After the male chases the female to the nest, the female begins the spawning process. She lays eggs for about one to two hours, and then leaves the nest for the male to
fertilize the eggs. The eggs take approximately six to eight days to hatch (this time period can be affected by the temperature of water). Because of the
external fertilization, males usually care for the eggs. They also have responsibilities for eating fungi-infected or infertile eggs, and fanning the eggs. One experiment placed three juvenile anemonefish in a tank and observed their behaviors over the course of a month. The researchers drew conclusions about the fish's social hierarchy based on signs of dominance such as aggressive or appeasing behaviors, occupation of territory in the tank, and body mass increase. The dominant fish grew larger compared to lower-ranked fish, suggesting the lower-ranked fish experienced growth suppression. In addition, a difference in the fish's levels of certain steroids suggested that lower-ranked individuals also experienced reproductive suppression. Another experiment demonstrated that when a female anemonefish is removed from the anemone, then the dominant male becomes the female and the next-highest-ranked male moves up the
dominance hierarchy to become the dominant male. Females use aggressive dominance behavior to control the males, preventing the formation of other females, and dominant males prevent juvenile males from mating. ==In aquaria==