The population structure and reproductive biology of crab Halimede tyche (Herbst, 1801) in Bitter lakes were studied. Crabs were monthly sampled during the period from January to December 2009. A total of 443 crabs were sampled, of them 249 were males (53.5 %), 138 non-ovigerous females (29.7 %), and 78 ovigerous females (16.8 %). Males were found to be larger than females. The overall males: females sex ratio estimated 1:1.2. The male of Halimede tyche attained 30.7 mm at first maturity, while female was 24.5 mm in size. The gonado-somatic indices of males were higher than that of females. Spawning season in both sexes extended from May to August. An increase in oocyte diameter was recorded in April (280 μm) and continued to reach the maximum value in June with an average of 397 μm. The absolute fecundity ranged from 10641 to 57810 eggs for crab size ranging from 22.2 to 36.5 mm.