ASSESSMENT OF WATER QUALITY OF SOME AQUATIC SYSTEMS IN NORTHEAST ALGERIA BY USEA NON-TARGET FISH Gambusia affinis DURING THE BREEDING PERIOD GROWTH AND BIOMARKERS RESPONSES

Biological control is a means of preserving biodiversity and eradicating vector species of diseases such as Anopheles, which cause Malaria. The fresh-water fish Gambusia affinis has been introduced into rivers around the world to control Culex larvae. This study aims to evaluate the responses of G. affinis from different sites due to their proximity to polluting sources by measuring growth (total height and weight), metric indices:gonadal-somatic index (GSI), hepato-somatic index (HSI) and condition index (K). It, also, investigated the response of two biomarkers: glutathion-S-transferase (GST) in the liver and acetylcholinesterase (AChE) in the head of adults females and males of G. affinis (Cyprinodontiforme: Poeciliidae).The species was collected during the reproduction period (sexual activity) in three sites different by their level of exposure to pollution sources: Messida River, a reference site located in a protected area, and two other site near to anthropogenic activities, El Karma and Sidi Brahim. The results obtained reveal that the Messida river site shows a better growth with the highest GSI and K compared to the other study sites. The data of the HSI revealed lower values at the same site. Biomarker measurements revealed higher GST induction, AChE inhibition, and a level higher MT at the Sidi Brahim. We conclude that the Sidi Brahim site is the most polluted followed by El Karma and finally the Messida River. The study of the different parameters in the two sexes revealed that the females of G. affinis were more robust than the males.