Captive hybridization of two geographically isolated pygmy angelfish species, Centropyge fisheri and Centropyge resplendens.

This study documents the rearing of two pygmy angelfish species, Centropyge fisheri and Centropyge resplendens, and the early life history and reproduction of their hybrid offspring. A C. fisheri female, collected from Hawaii, and a C. resplendens male, captive-bred from parental stock collected from Ascension Island, were maintained at the hatchery facility for 7 months. Continuous spawning was achieved at a photoperiod cycle of 14L:10D and a water temperature of 26.5 degrees C, range +/-1 degrees C. Over the 110 day period, the C. fisheri female spawned 102 times, 57% of which resulted in embryos (fertilized eggs). The mean +/-s.d. fecundity per spawn was 730 +/- 459 eggs (range 52-1967). Fertility (% eggs that developed into embryos) of all eggs that were preserved was 22.4 +/- 25.6%. A total of 235 hybrid juveniles were raised through metamorphosis with an average larval survival of 16.4%. Eight F(1) hybrid juveniles isolated for further study began to display signs of reproductive behaviour c. 300 days post-hatch (dph). Spawn resulting in non-fertile eggs were first obtained 319 dph, and fertilized eggs developing into embryos were obtained after 411 dph from at least two female individuals. While no attempt was made at rearing the F(2) larvae, embryo and larval development were normal up to 8 dph. Reproduction and development observed for all hybrid generations in this study were normal, similar to other Centropyge species and indicates a very close phylogenetic relationship between what are currently considered distinct species, e.g. C. fisheri and C. resplendens.