Effect of salinity on spawning of Yellow fin sea bream (Acanthopagrus latus) in spawning tanks

Abstract

Salinity effects on brooders spawning, growth and survival rate of yellow fin sea bream (Acanthopagrus latus) fingerlings was studied in Khouzestan Marine Fishes Research Station (Bandar -e – Imam) in 2002-2003. More than 200 brooders were caught in Mahshar creeks using hook, and 6 males and 3 females of brooders were introduced to each 4 tons tank. The experiments were carried out using 3 salinity treatments (30 ± 1, 35 ± 1 and 40 ± 1 ppt) in 3 replications. Survival rate of brooders in 4 tons tanks during late January to 4 th April was estimated more than %90 in all salinities and the maximum rate was observed in 30 ppt treatment. Spawned brooders percentage in 40 ppt was more than the two other salinities, and spawning occurred in all three replications of this treatment. In all treatment, spawning started from early march (late lunar month) at 19°c and continued at 23°c. Duration and replication of spawnings in 40 ppt were more than other salinities, and last about 20 days. Released eggs (2461046), amount of eggs production per day (66413), average number of eggs per brooder (312914), and average eggs per kg body weight (649460) were found in 40 ppt more than other salinities. Floating eggs ratio was more than %90 in 40 ppt and it was significantly different to the others. Fertilization and Hatching rates in 40 ppt treatment (86.7 , 67 respectively) were more than 30 and 35 ppt but there was no significant difference. All spawnings cases , released eggs hatched.