الفهرس 
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Abstract
The puffer fish (Tetraodon lineatus) is one of those species found in Lake Nasser, it is considered a discard from the catch. Biological and population dynamics data are required to understand the Puffer fish behavior and to put a management plan to reduce the damage that caused by the Puffer fish to the fishermen. Age determinations based on vertebrae readings, showed that the life span of the fish is eight years. The most frequent age group age group one. The estimated von Bertalanffy growth parameters were L∞ = 57.2 cm, K = 0.14/y, to = -1.89/y, w∞ = 3116.1 g and Ø = 2.67, for T.lineatus data. The fish grows pattern exhibited a negative allometric type (b<3). Females are dominate than males representing 63% of the total fish with sex ratio 1: 1.7. This species had a spawning season begins in March to July for both sexes. The dominant length groups are 16cm: 24.9cm and 27cm: 32.9 cm. their first sexual maturity at the following lengths 25 cm, 23 cm for males and females respectively when they were 2.03, 1.62 years old. The total mortality, natural mortality and fishing mortality coefficients were estimated as 1.05, 0.40 and 0.65 year-1 respectively. The length at recruitment was 13.8 cm, corresponding to age (tr) of 0.30 year. The length at first capture at 50% was 16.2 cm. The estimated current exploitation rate (E = 0.61). In order to improve fish production and maintain puffer fish stock in Lake Nasser, and maximize its added value, we recommend Transform the puffer fish from discard to by-catch, the skin of Puffer fish is a useful source to natural leather manufacturing, It can be used as a processed feed, and Puffer fish is an important source to the pharmaceutical industry.