Impact of certain plants and synthetic molluscicides on some fresh water snails and fish
Mosta-Fa, B.B.; el-Deeb, F.A.; Ismail, N.M.; el-Said, K.M.
Journal of the Egyptian Society of Parasitology 35(3): 989-1007
2005
ISSN/ISBN: 1110-0583 PMID: 16333905 Document Number: 585853
The LC50 (78, 85 ppm) and LC90 (88, 135 ppm) of Anagallis arvensis and Calendula micrantha respectively against Biomphalaria alexandrina were higher than those against the non-target snails, Physa acuta, Planorbis planorbis, Helisoma duryi and Melanoides tuberculata. In contrast, the LC50 of niclosamide (0.11 ppm) and copper sulfate (CuSo4) (0.42 ppm) against B. alexandrina were lower than those against the non-target snails. The percent mortality among non-target snails ranged between 0.0 and 20.0% (when sublethal concentrations of CuSo4 against B. alexandrina were mixed with those of C. micrantha) and between 0.0 and 40.0% (when mixed with A. arvensis). Mortalities ranged between 0.0 and 50.0% when Niclosamide was mixed with each of A. arvensis and C. micrantha. A. arvensis induced 100% mortality in Oreochromis niloticus after 48 hours exposure and after 24 hours in Gambusia affinis. C. micrantha was non-toxic to the fish. The survival rate of O. niloticus and G. affinis after 48 hours exposure to 0.11 ppm of niclosamide were 83.3% and 100% respectively. These rates were 91.7% and 93.3% respectively when each of the two fish species was exposed to 0.42 ppm of CuSo4. Mixture of sub-lethal concentrations of A. arvensis against B. alexandrina and those of niclosamide or CuSo4 at ratios 10:40 and 25:25 induced 66.6% mortalities in O. niloticus and 83.3% at a ratio of 40:10 . These mixtures caused 100% mortalities in G. affinis at all ratios. A. arvensis:CuSo4 mixtures at 10:40 induced 83.3% and 40.0% mortalities in O. niloticus and G. affinis respectively and 100% mortalities in both fish species at ratios 25:25 and 40:10. A mixture of sub-lethal concentrations of C. micrantha against B. alexandrina and of niclosamide or CuSo4 caused mortalities in O. niloticus between 0.0 and 33.3% and between 5.0% and 35.0% in G. affinis. The residue of Cu in O. niloticus were 4.69, 19.06 and 25.37 mg/kg fish after 24, 48 and 72 hours exposure to LC0 of CuSo4 against B. alexandrina respectively.