Results and Discussion. The Anova test showed that the B. racemosa extracts
extracted in methanol and water affect significantly on hatchability of P. canaliculata eggs
(p < 0.01), where the hatchability of P. canaliculata eggs were decreased with increasing
concentration of B. racemosa extract both in the methanol and water solvents. The Tukey
test showed the concentration of 100 ppm were resulted in lower hatchability compared
to other concentrations, however this result was not significantly different at a
concentration of 80 ppm in both solvents (Table 1).
The inhibition of egg hatchability may be due to the active substances in the B.
racemosa extracts. Egg capsule of the snail is formed by a calcium carbonate layer
(Cowie 2006), the layer serves as a membrane for gas exchanges from the inside of the
egg to the environment or vice versa. In addition, the egg shell acts as an effective
barrier against losing of water during the incubation period in the air without blocking the
supply of air (Turner 1998).
The study revealed that increasing the concentration of B. racemosa seed extracts
were decreasing the hatchability of P. canaliculata eggs. The decreasing of egg
hatchability was assumed due to the extract covering the surface of the egg capsule
blocking the air supply and cause the embryo to die. This is in agreement with the
Rawlings (1999) and Bigatti et al (2010) who reported that the number of embryos of
Neo Gastropod molluscs decreased when the air supply decreasing. In addition, Wu et al
(2005) studied the morpholine (C4H9NO) to inhibit hatching of P. canaliculata eggs. They
reported that this material inhibit hatching of P. canaliculata eggs effectively, however,
morpholine shows chronic effects in humans especially toxic to lungs and mucous
membranes (Shea 1939), while the B. racemosa seed extracts are environmental friendly
and non toxic to human and therefore suitable for controlling P. canaliculata.