A detailed study of chromosomes of two species of Indian inland fish revealed the chromosomal number and type. It describes the relation between the two species. Their peculiar morphological characters have been recorded. These karyological observations provide strong evidence to conclude that the two species are closely related and have phylogenetic links.
Crude extracts of three plants Citrullus colocynthis, Leucas aspera, and Strychnos nux-vomica were screened for their larvicidal activities against the third instar of Culex quinquefasciatus. The mortality rate of the mosquito larvae was evaluated against the three botanicals at different periods of exposure (24h, 48h, and 72h). Hexane, Chloroform and Ethyl acetate were used as solvents for the crude extracts. C. colocynthis showed the maximum larvicidal effect (100% mortality) in 750 ppm and 1000 ppm in hexane extract at 24h period of exposure. L. aspera also showed the same activity in hexane extract at 24 h, while S. nux-vomica showed slightly lower effect.
Pesticide pollution in aquatic environment brings about sudden and drastic changes in aquatic organisms. The indiscriminate use of pesticides in agricultural operations affects the aquatic environment to a greater extent. Pesticides like endosulphan and monocrotophos which are widely used in agriculture affect fish population drastically. In the present study the effect of monocrotophos on the enzymes Acid Phosphatase, alkaline phosphatase and lactate dehydrogenase of Ctenopharygodon idella has been estimated. The activity was found to be decreased significantly due to Pesticide intoxification.