Biological and biochemical studies in Bullinus truncatus snails collected from Saudi Arabia

ABSTRACT

In Saudi Arabia three species of snails namely, Bulinus truncatus, B. beccarii and B. wrighti, have been incriminated as intermediate hosts for Schistosoma haematobium. The present work was conducted on Saudi Arabian B. truncatus snails, [growth, survival rate and fecundity] in addition to comparison of some enzymatic activities between B. trunctus [control and infected with S. heamatobium] snails from Egypt and Saudi Arabia. Under laboratory constant temperature 24 +/- 1°C and after 20 weeks, the results show that the growth of Saudi Arabian Bulinus snails can be differentiated into two groups the 1[st] one [70%] of the tested snails showed a total growth of 600% and 2[nd] one [30%] with a growth rate of 327.8%. The snails egg laying started at the 10[th] and 20[th] weeks without differences in their sizes [3.6 +/- 0.86 and 3.85 +/- 0.82] for these two groups respectively. A considerable survival rate was recorded for the 1[st] group after 20 weeks [68%] with mean life span 10.8 +/- 6.7 weeks. A convenient number of eggs were laid by survived snails with a net reproductive rate [Ro] of 129.12. In Egyptian and Saudi Arabian B. truncatus snails, the activities of enzymes, aspartate aminotransferase [AST], alanine aminotransferase [ALT] and alkaline phosphatase [AlkP] were significantly [P<0.0001] altered in the tissue homogenate of infected snails compared to control ones, in contrast acid phosphatase [AcP] was increased in infected snails than control ones, Both snail strains were classified as oxyphilic, poorly adapted to anaerobic conditions with the AST/ALT ratio higher than 2 in both control and infected ones