BIOLOGY AND TOXICITY OF THE PUFFERFISH LAGOCEPHALUS SCELERATUS (GMELIN, 1789) FROM THE GULF OF SUEZ

Some biological aspects of the pufferfish Lagocephalus sceleratus were studied and correlated with the toxicity of the fish. A sample of 176 fish with total lengths ranging from 18.5 to 78.5 cm were collected from commercial catches at the Attaka fishing harbor between October 2002 and June 2003. Length weight regression parameters for males, females and all individuals were estimated. Modal progression analysis output indicates ten distinct age groups. The parameters of the von Bertalanffy's growth model were L∞ = 81.1 cm and K = 0.26 per year. The overall sex ratio of males to females was 1: 1.3. The spawning takes place during summer and the size at which 50% of fishes are mature is 42.1 cm for males and 43.3 cm for females. Analysis of the diet composition showed that the fish is carnivorous and the maximum feeding intensity was attained in April. The toxicity of the gonads of twenty five specimens in different sexual maturity stages was assayed. The results showed that the highest toxicity scores were recorded during April, May and June for both sexes during the spawning season. The highest toxicity scores were recorded at the spawning stage of maturity (3500 MU/g for males and 3950 MU/g for females). While most of the specimens in maturity stage II (developing stage) were found non toxic.