Captive maturation, breeding and seed production of the brackishwater ornamental fish silver moony, Monodactylus argenteus (Linnaeus, 1758)

Abstract

Silver moony, Monodactylus argenteus (Linnaeus, 1758), belonging to the family Monodactylidae, has high significance in the ornamental fish industry. The present study provides the details of captive broodstock maturation, induced breeding and larval rearing of this species for the first time. Juveniles were collected from wild and raised to adults in net cages. Female with oocyte diameter =500 µm and oozing males were selected in the sex ratio of 1:2 (female: male) and induced to spawn using a single dose of LHRHa. Spontaneous spawning and fertilization were observed after 36 to 40 hr of hormonal induction. The average fertilization and hatching rates were 83.50 ± 4.37% and 70.83 ± 5.19% respectively. The incubation period was observed to be 18 to 20 hr at a temperature of 29 ± 1.8°C. Newly hatched larvae measured 1,630 ± 0.20 µm in length. Larval rearing was carried out in 500‐L circular fibre reinforced plastic tanks using a green water system. Larvae were stocked at 5 L−1 in larval rearing tanks. Initial mouth opening and complete yolk absorption were observed at 48 and 96 hr post‐hatching respectively. Larval feeding was done using live feeds, rotifer and Artemia nauplii. Metamorphosis began on 23 dph, and 100% larvae became juvenile on 32 dph with an average survival rate of 49.6 ± 8.73%. These findings on the development of captive seed production of silver moony would pave the way for mass scale production and reduced exploitation of wild stocks.