Some Biological Aspects and Population Parameters of the Slender Emperor Lethrinus variegatus (Family Lethrinidae) from the Gulf of Aqaba, Egypt

Egyptian fisheries including aquaculture represent an important sector in the national economy, and it is a source of employment. All studies dealing with the stock assessment and fisheries management in Egypt confirmed the over-exploitation situation for most commercial stocks leading to a serious decrease in domestic fish production from natural resources.  This situation made the fisheries managers in Egypt explore new fishing areas to enhance fish production in Egypt. The present work was undertaken as a part of NIOF scientific plan about the Gulf of Aqaba fisheries and how rationally it can be exploited.  Fish biology and population dynamics are fundamental for fish stock assessment and its management. Some biological and dynamical parameters of Lethrinus variegatus from the Gulf of Aqaba, Egypt were investigated to assess its exploitation status. Comparisons of age and growth characteristics recorded no significant differences (P> 0.05) between the sexes. The von Bertalanffy growth parameters for pooled data were K= 0.51/ year, L∞= 25.79cm TL and t₀= -0.387 year. The mean size at which the fish attained sexual maturity for L. variegatus was 16.33cm TL. The mean size at first capture was 17.31cm,  which was greater than the size at first sexual maturity, indicating the healthy status of L. variegatus stock in the Gulf of Aqaba. The fishing mortality rate for L. variegatus (0.80/ yr) was substantially greater than the target F_opt (0.51/ yr) and limit F_limit (0.67/ yr) estimates. The slender emperor stock was in its optimum situation as the current exploitation rate was 0.44/ yr. The results of the study are important to fisheries management authorities in the region since they will contribute to planning the regional fishery management policies in Egypt.