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Abstract In the Gulf of Suez, Sepia savignyi is the most common species in the cuttlefish. The age and growth of the cuttlefish S. savignyi caught by the demersal trawl fishery in the Gulf of Suez were investigated during the fishing season 2014/2015. Aging was determined by applying the Bhattacharya’s method (1967) based on length frequency data for a sample of 452 ranged from (4.5 to 23 cm) for males and (3.9 to 29 cm) for females in mantle length. The aging extends to three, four and four years with zero groups of males, females, and sexes combined, respectively. The mean von Bertalanffy growth parameters as estimated by four different methods, L∞ were 24.28, 33 and 32.11 cm, W∞=1113.04, 2736.48 and 2523.47 gm. And k value were 0.61, 0.42 and 0.51/ year for males, females and sexes combined, respectively. The sex ratio was 1:1.5 males: females. The size at first sexual maturity (DML50) was 11.9 and 8.4 cm for females and males, respectively. The GSI indices show that the females and males have two peaks in the year-round spawning period where first of these is in April (3.5%) and (2.2%) and the second is in December (4.1 %) and (2.4%) for female and male, respectively. Five stages of gonad maturation were established for the females and males, namely immature (I), maturing (II), mature (III), spawning (IV) and spent (V) based on macroscopic examination. Oogenesis of oocyte demonstrating seven stages of maturity in females were recognized oogonia, early primary oocyte, late primary oocyte, previtellogenic oocyte, vitellogenic Oocyte, advanced vitellogenic oocyte and ripe oocytes. Spermatogenesis of testes divided into spermatogonia, primary and secondary spermatocytes, spermatid and spermatozoa. The estimated value of total mortality, natural mortality, fishing mortality and exploitation rate, Z=1.57/year,0.99. /year, 1.09 /year, M=0.32, 0.23 and 0.25/year, F= were 1.25, 0.76 and 0.84 /year and E =0.79, 0.77 and 0.77 /year for males, females and sexes combined for Sepia savignyi, respectively. |