الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 162 |  |  |
| | | from | 162 | | |
Abstract
Length frequency distribution data of blue swimming crab Portunus pelagicus
(Linnaeus, 1766) from Suez Gulf waters were based on regular sampling every month from the
landings of trawlers operating in the Ataka fishing port-Suez Gulf, and also trammel net boats
operating in the Salkhana fishing port-Suez Gulf, during the fishing season 2017/2018.To
estimate the growth and mortality parameters for the Portunus pelagicus. The combined length
frequency data of P. pelagicus were n= 537. The data were measured in carapace width (CW)
in cm. the analyses were based on FISAT stock assessment computer software package. The
von Bertalanffy growth function parameters CW∞=23.86 cm (CW) and K =0.89 year-1 (using
average of powell-Wetheraal, Shepherd and ELEFAN methods) for pooled data. While males
reached CW∞=23.83 cm and K =0.78 year-1. Females estimated CW∞=20.44 cm and K =0.93
year-1. And the t0 value was calculated at (0.27, 0.01 and 0.29) for males, females and pooled
data respectively, Examination of population characteristics revealed that Males of Portunus
pelagicus grow more than females of the same species. Females of Portunus pelagicus
fecundity reached 650000 eggs per mature female .Based on the VBGF growth parameters the
total, natural and fishing mortality were calculated at 2.89, 1.09 and 1.8 year-1, respectively for
pooled data. The total mortality calculated by taking the average of (Pauly, Jones and Hoeing
Methods). While natural mortality calculated by taking the average of (Pauly, Rikhtar, Urisin
and Taylor functions). The fishing mortality of pooled data shows greater average than natural
mortality which shows that the current status of blue swimming crab is in exploitation state and
for extra declare exploitation ratio were estimated for pooled data, males and females (E =
0.62, 0.63, and 0.66 / yr. respectively), these values seem to be over the optimum level of
exploitation (Eopt. = 0.50 / yr.). In the light of above results we may assume that the P.pelagicus
fishery from Suez Gulf waters are was in overexploited state. It is recommended that some
management steps should be taken to maintain the blue swimming crab fishery stock from Suez
Gulf waters for the future generations.