الفهرس 
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Abstract
Values of the condition factors for the Gulf of Suez population indicate that these species showed a good growth pattern and condition in its habitats. The absolute condition factor showed monthly variation as the high values were recorded during March, and May which is justly before and during spawning season while the lowest values were recorded in January.
The results of the size frequency distributions of combined sexes of D. russelli collected from the Gulf of Suez showed that the population exhibits a mode at 19-19.9cm long (about 17%).
The present study revealed that the maximum age of D. russelli estimated by length frequency was four years old, which were considered as distinct age groups with mean lengths of 15.25, 18.32, 20.50, 22.63cm. The first and second age groups are the most dominant age groups in the investigated species.
The growth pattern of D. russelli indicated that, both males and females attained their highest increment in length (15.52 cm) at the end of the first year of life, after which the annual increment in length decreased gradually
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with the increasing in age until it reached its minimum value at the end of the 4th year of life. The poor growth rate in length after the first year of life may be associated with the onset of maturity, which often causes a discontinuity in the growth curve.
Growth in weight showed that the low values were at the first year of life 33.14g. The annual increment of weight increased with the increasing in age until it reached its maximum value at the end of age group II, 82.28g, then decreases again gradually until it reached its minimum value 32.05 at the end of the length group IV.
The theoretical maximum length value (L∞ = 28.786 cm) was far to the size of the largest fish examined and the growth coefficient value (K = 0.77 year-1) indicated relatively very fast growth rate.
The age composition of D.russelli showed that age group II constitutes the bulk of the Gulf of Suez population.
The total mortality coefficient (Z) was 4.61 Y-1 for the Gulf of Suez population. The natural mortality (M)
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value for the population were 1.39. The fishing mortality (F) was 3.22 for Gulf of Suez population.
The result of exploitation rate (E) for the studied population showed that the fisheries of D. russelli in the Gulf of Suez is almost at (over) the optimum exploitation rate (0.7).
Length at first capture (LC), in the present work, was estimated as 17.2 cm for combined sexes. The corresponding age tc were 1.202 year. The length at first capture is smaller than the length at first sexual maturity (Lm= 17.5 for combined sexes). While the smallest length represented in the catch of D.russelli from the Gulf of Suez is 11.2 cm. Length at recruit is estimated to be Lr=11.2cm and age at recruit was estimated to be equal Tr=0.66 year.
As the results indicated that the length at first capture is smaller