SOME BIOLOGICAL ASPECTS OF FOUR CICHLID SPECIES IN LAKE MANZALAH

SOME BIOLOGICAL ASPECTS OF FOUR CICHLID SPECIES IN LAKE MANZALAH
relationship. The computation of the coefficient of condition for these species
was based on the formula
W = aLb Le Cren (1951) and Ricker (1975)
Where W = weight in grams.
L = total length in cm.
a and b are the regression coefficient.
The relative condition factor (Kb) \vas determined from the equation,
Kb= W Le Cren (1951)
w
\\,There V.i = the observed weight and
\v = the calculated weight obtained from
\\7 = aLb
For the analysis of the food content, the gut from 447, 1075,442 and 459
fish namely S. galilaeus, T. zULU, O. nUoticus and O. aureus respectively were
used. These specimens were collected monthly from different regions of the
lake and preserved in 50/0 formaline. The gut content was examined using a
research microscope and the different food items were identified using the
occurrence method. The number of stomachs in which each food item occurred
was recorded and expressed as a percentage of total number of stomach
examined as used by Abdel-Malek (1968, 1971, 1972). The variation ofthe gut
contents was treated in respect to species and seasons.