Abstract
Quinalphos, an organophosphorous pesticide, was administered orally to sexually mature male Whitethroated Munias at different doses (5μg-, 10μg- and 20μg/100g body wt./day) for 1-, 5-, or 10 day(s). Testicular responsiveness to the treatment in each group was analyzed by comparing the testes with control (vehicle treated) birds. A significant decrease in the paired testicular weight, and in the number of seminiferous tubules containing healthy germ cells was noted following the treatment of each dose of pesticide for 5- and 10 days. A number of degenerative changes in the testicular germ cells were found in different groups of quinalphos ingested birds, but no degenerative feature could be ascribed as a marker to the level of exposure. The activity of acetylcholinesterase (AChE) in the testes of quinalphos treated munias was inhibited in a dose- and duration-dependent manner. A significant negative correlation was found between testicular AChE activity and percentage of degenerated germ cell containing tubules. However, no conspicuous difference was noted in the Leydig cells of the testes in the control and treated bird groups. The results of the present study indicate that ingestion of quinalphos is injurious to the gametogenic functions of the testis in a wild passerine bird and that the antigonadal action of the pesticide may be pharmacological in origin.
