The developmental stages of spinecheek anemonefish are egg, larvae, young and adult. The transparent, elliptical eggs are 3-4 mm in size. Anemonefish hatch with advanced alimentary canals and feed on the yolk, which usually lasts for about 3 days. Five days after hatching they develop supranuclear inclusions around the hindgut, which suggests pinocytotic digestion of protein. Between 3 to 5 days after hatching is the period of highest mortality stage for anemonefish if they cannot find food. It is also the time when they transition from endogenous to exogenous feeding. Seven days after hatching they attain gastric glands and by the 9th day they have supranuclear vacuoles that indicate exogenous digestive capabilities. Spinecheek anemonefish hatch 6 to 7 days after fertilization, and then undergo a 7 to 14 day pelagic larval stage. After fertilization, they complete the development of the olfactory organ in 19 days, retinal differentiation in 20 days and skeletal ossification in about 22 days. Spinecheek anemonefish develop more rapidly than other anemonefish species. Their eyes develop especialy rapidly. Vision is directly correlated with the ability to attain food because most larval fish are visual feeders. Olfactory cues are used to detect host anemones. During the larval stage spinecheek anemonefish live on the water surface where they are transported by currents.
Metamorphosis occurs when anemonefish leave surface waters and swim to the sea bottom. It then takes on the color pattern of a juvenile. This process usually takes about one day. This marks the beginning of the settlement period, in which individuals seek out an uninhabited anemone host.
Spinecheek anemonefish, like other anemonefish species, are protandrous hermaphrodites, which means that they change from male to female. Females have gonads that function as ovaries with leftover male testicular tissue. In the case of spinecheek anemonefish, males may be half the size of females and their gonads have dormant ovarian cells as well as functioning testes.
Development - Life Cycle: metamorphosis