An investigation on feasibility of introduction of Tilapia to aquaculture industry of inland brackish waters at desert areas of Iran

Abstract

Tilapia is the third most cultured fish in the world. Studies about tilapia were started in Iran from November 2008 for the first time. Immature black Nile tilapia, Oreochromis niloticus, and red hybrids were stocked in 6 cylindrical 3m3 fiberglass tanks from September 2009, for breeding. Samples were stocked in 27±0.5ºC water temperature, 11.5±0.5ppt salinity, 2500lux light/day (18h L: 6h D), sex ratio of 1:3 (male: female) at 5/m3 density. Body weight and total length of spawned females were measured. Eggs were incubated in conical glass jars, after counting. Length of the large diameter and weight of 25 eggs were measured in the laboratory. Absolute and relative fecundity, spawning frequency of both black and red broodstocks, incubation period and hatching percent of the eggs were acquired. Power regression between body weight and total length of spawners, Pearson correlation coefficients of body weight and total length against absolute and relative fecundity, weight of egg clutch, length and weight of egg were obtained. Black and red spawners were compared for fecundity and egg quality, by t-student test (p<0.05). Spawning frequencies and optimum ranges of length, weight and age of spawning in black and red female tilapias were defined.