Glucose, total protein, total lipids, the enzymes sCOT, sGPT, gserum Ca++ and Pi were determined in the haemolymph of
both Leptodius exartus (H. Mime Edwards, 1834) and Thalamita poissoni Audouin, 1826, individuals that collected from the Gulf of Suez. The studied parameters were 42.22±17.06 mg/dl for glucose,3.92±0.61 g/dl for total protein, 2.37±0.29 g/dl for total lipid,26.02±4.00 lU/I for sGPT, 14.33±2.3 lU for sCOT activities, 79.02±18.38 mg/dl for Ca++ and 7.34±3.21 mg/dl for Fl in L. exartus.While in T. poissoni these values were 98.17±38.34 mg/dI, 3.94±0.59
g/dl, 116±0.17 g/d 23.30±0.14 lU/1, 28.60±6.24 lU/I, 69.35±9.78 mg/dl and 23 .30± 14.25, respectively.
There are statistically significant differences between the two species in the haemolymph parameter concentrations. Both glucose and total lipid were highly significant, while a significant difference was recorded between sGPT, sGOT and Pi in the two species and no significant difference was detected between total protein and Ca++ in haemolymph of the two species.