Reproductive Behavior of the Anemonefish Amphiprion melanopus on Guam

Ross, R

Nineteen breeding pairs of the anemonefish Amphiprion melanopus and their nests were observed continuously on Guam for approximately one year. A. melanopus are monogamous and apparently protandrous hermaphrodites. Nest preparation consists of both anemone biting and substrate biting. Spawning occurs 2-3 hours after sunrise and lasts 1.5 hours. Eggs are mouthed and fanned by the male during the incubation period, but there is no nocturnal egg care. Hatching occurs 1.5 hours after sunset on the seventh or eighth day of incubation. Spawning activity peaks near the first and third quarters of the lunar cycle. Consequently, hatching activity peaks near full moon and new moon at the time of day when high spring tides also occur. Nocturnal hatching on high spring tides is interpreted as a mechanism for reducing predation on hatchlings due to the inactivity of some planktivores at night and the more effective dispersal of hatchlings away from the nest during high tides. There is no seasonal periodicity in spawning activity. An average of 2 spawns per lunar month per pair was observed. Estimated annual fecundity is 7,200 eggs per year for stable pairs.

Reproductive Behavior of the Anemonefish Amphiprion melanopus on Guam

Series