Study on the reason of striped mullet (Mugil cephalus) larvae mortality and the production of its fingerlings

In this study, nine years old farmed broodstocks of striped grey mullet have been induced artificially by hormones. Eight experiments of artificial propagation carried out during three months (from October to February) in 2003. The hormones used for males were HCG and 17-α-Methyltestosterone and to induce females the hormones such as LHRH-α2, HCG and CPH were used. During these experiments, 27 females injected which 22 of them spawned along with larval production. Water temperature and salinity were 20-23°c and 32 ppt during artificial propagation respectively. For larval culture, two different experiments carried out which final larval density in tanks, water temperature and salinity were 20 in/liter, 22-24°c and 32-33 ppt respectively. Larvae fed with live foods such as Nannochloropsis oculata , Brachionus plicatilis, Artemia nauplii with density of 500000 cell/ml, 20 ind/ml and 3-200 ind/liter respectively. Water exchange in larval culture tanks during first week was 10 percent of tank volume, and this amount in the second and next weeks were higher which have been 2030 and 40-50 percent of tank volume respectively. At the first experiment of larval culture, the tanks with maximum depth of 80 cm used that whole larvae died after 12 days post hatching; whereas at the next trial, three numbers of 4000 liters fiberglass black color tanks with maximum depth of 120 cm used which tend to the survival rate of 0.9 percent after 55 days post hatching