After incubating for 6-7 days, the eggs of A. percula are ready to hatch. Just before then, however, the embryo is visible through the transparent egg membrane. The two noticeable features at this stage are the silvery pupils contained within the large eyes and the red-orange yolk sac (Fautin and Allen, 1992). After hatching, the larva is about 3-4 mm total length and transparent except for the eye, yolk sac, and a few scattered pigments. The newly hatched individual initially sinks to the benthic environment but quickly swims to the upper surface of the water column using a process called phototaxis. Essentially, the larva is able to orient itself using the shine from a moonlit night. At this point, the larva spends a week floating among the plankton and is passively transported by ocean currents (Fautin and Allen, 1992). The larval stage of A. percula ends when the young anemonefish settles to the sea bottom approximately 8-12 days after hatching (DAH). Compared to other coral reef species, this is a relatively short period (Wellington and Victor 1989).
The juvenile stage of A. percula is characterized by a rapid development of color schemes. The white barring pattern that is unique to this species begins to form around 11 DAH and may correspond to the fish’s first association with its host anemone (Elliott et al., 1995). Consequently, contact with the anemone stimulates A. percula to produce its protective mucous coat (Elliott and Mariscal, 1996) (See Behavior section for a complete elaboration on acclimation and protection from anemone nematocysts). The entire metamorphosis from larva to juvenile is usually completed in a day (Fautin and Allen, 1992).
Development from juvenile to adult is highly dependent on the social hierarchy of the “family group.” Each host anemone is often occupied by a mating pair plus two to four smaller fish (Fautin and Allen, 1992). Aggression between the dominant female and her mate is minimal, thereby causing little expenditure in energy. Each male, however, bullies and chases the next male of smaller successive size until the smallest individual is driven away from the host anemone. As a result, energy that could be used for growth is instead appropriated for competitive encounters. The adult pair essentially stunts the growth of juveniles (Myers, 1999).
Like other anemonefishes, the uniqueness of A. percula development lies in adult metamorphosis from male to female (protandrous hermaphroditism). All anemonefishes are born as males (Wood and Aw, 2002; Fautin and Allen, 1992; Rosenberg and Cruz, 1988), and the largest of the group reverses sex to become the dominant female. The second largest male subsequently becomes the dominant male. In instances when the female dies, the dominant male reverses sex and all other subordinate males move up in the hierarchical ladder.
Development - Life Cycle: metamorphosis