The chemical was applied to reach final concentrations of 5, 10 and
20 ppm, respectively in 3 roadside ditches. The non-target snail
species, F. martensi martensi, died in small numbers; no effects on
other animals was detected including tadpoles, fish and shrimp, even
though the concentrations used were higher, up to 20 folds of the
lethal concentrations used in laboratory testing. At 14 days after
Bayluscide application, B. siamensis goniomphalos in ditches 1, 2 and 3
had percentage mortality rates of 10.94, 20.00 and 31.25%, respectively.
Some non-target aquatic animals in treated water bodies
exhibited aberrant behavior, such as cyprinoid fish which began
swimming upside down for a few minutes then became normal and
some of them jumped up over water surface. No visual effects on
aquatic plants were detected.
3.4. Histopathological investigation of Bayluscide on B. siamensis
goniomphalos
Bayluscide caused pathologic changes in B. siamensis goniomphalos
tissues including detachment of cilia of epithelial layers of digestive
tract, vacuolated digestive glands and decreased number of calcium
cells (Fig. 3).