AN INVESTIGATION ON BREEDING OF CULTURED NILE TILAPIA, oreochromis niloticus IN BRACKISH WATER, IRAN

Nile tilapia Oreochromis niloticus samples were stocked from September 2009 to January 2011. During the study period, water salinity, temperature, pH and oxygen saturate were fixed at 11.5ppt, 27±0.5°C, 7.6-8.1 and 100%, respectively. Fish were fed using 40% protein food under 18:6 (L:D) 2500lux light regime. Total length and weight of the spawners, absolute and relative fecundity, egg weight and diameter and spawning intervals were investigated. Pearson correlation coefficient between total length and weight of brooders against absolute and relative fecundity, wet weight of an egg, egg clutch and egg diameter were studied (p<0.005).

Tilapias are the second cultured fish in the world in recent years. Nile tilapia, O. niloticus is the most common tilapia widely cultured in many tropical and subtropical countries and consists up to 80% of cultured tilapias of the world (FAO, 2010).

Nile tilapia samples were entered to Iran at December 2008 for the first time. Studies about the feasibility of introduction of tilapia to inland aquaculture in Iran were begun in National Research Center of Saline Water Aquatics in Yazd province at the center of Iran.

The reproductive aspects of tilapias are widely investigated in different parts of globe but it hasn't any history in Iran. The absolute fecundity, spawning intervals and hatch percents of cultured O. niloticus are measured at brackish water condition, in the present study.