"Annals Of Agricultural Science"
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Age, growth and mortalities of the redbelly tilapia Tilapia zillii in Bardawil lagoon, North Sinai, Egypt.

Gaber D. I. Hassanen1, Mohamed S. Ahmed 1and Doaa K. K. Ali1

Abstract


The age, growth and mortalities of the redbelly tilapia Tilapia zillii in Bardawil lagoon were studied using 1772 specimens ranging from 8 to21.3cm Total length (TL)and 10 to 165 g total weight, They were collected from May to December, 2015.The relationship between length and weight estimated as W = 0.0189L 2.99. Age determined by using scales’ reading technique for 312 individuals samples and the longevity of this species was found to be 5years. Growth in length and weight at the end of each year was recorded. The growth parameters of the von Bertalanffy equation were calculated as L∞=26.01, K=0.25yr-1, t0= -1.37yr-1 Total, natural and fishing mortality rates were 0.48 yr−1, 0.30 yr−1 and 0.18 yr−1, respectively.Maximum ages of combined sexes was 5 years. The current exploitation rate (E = 0.37) indicates that the stock of the redbelly tilapia in Bardawil lagoon was lower exploited.The length at first capture Lc was estimated at 14.4 cm. this show that the exploitation of low tilapia in Bardawil lagoon. The letter recommended should be banned fishing at least in length from 14 cm to give opportunity even once hatchery. As it should catch this fish ban sexually mature during the period from July to August, where hatched season in Bardawil lagoon.

Key words


age, growth, estimation of mortalities, Tilapia zillii, Bardawil lagoon, Egypt.s