reproductive behaviour and embryonic development of the citrinis clown goby (gobiodon citrinus) and blue sapphire damselfish (chrysiptera springeri)

It is estimated that less than 10% of marine animals marketed for ornamental purposes are originate from captive production. The development of reliable and sustainable hatchery procedures for the captive breeding of reef fishes is essential to reduce pressure on wild populations and also because rearing fish in closed systems is likely to lead to the production of hardier specimens that are far better in captivity and survive longer. To date, basic information is available only for few marine ornamental species and further research to elucidate species-specific developmental characteristics, environmental, physiological and immunological capabilities and tolerances of embryos and newly hatched larvae are necessary for the establishment and refinement of rearing techniques. The aim of this study was evaluate the reproductive behaviour and embryonic development of two popular ornamental species G. citrinus and C. springeri. Eight adults of each species were kept under controlled conditions for the establishment of breeders pairs. After, each pair was isolated to record the courtship behaviour, spawning period and the number of eggs produced. Results showed that both species under study are demersal spawners, with parental care, eggs are adhesive to the subtrate and capsule oval. For the G. citrinus the interval between successive spawns ranged from 5 to 9 days, eggs have 1.054 ± 0.023 mm length and 0.435 ± 0.005 mm width, hatching occurs on the night of five day after fertilization and the length of newly hatched larvae averaged to 2.250 ± 0,02 mm. For the C. springeri the interval between successive spawns ranged from 4 to 7 days, eggs have 1.04 ± 0.019 mm length and 0.505 ± 0.01 mm width, hatching occurs on the night of third day after fertilization and the length of newly hatched larvae averaged to 2,277 ± 0,07 mm. The development of captive breeding techniques for targeted aquaculture species requires a sound knowledge of their gamete physiology, embryology, and early larval ontogeny and this study provides for the first time technical information about breeding of G. citrinus and C. springeri and this can be a start point for the captive breeding of this species.