Biochemical and histological assessment of some heavy metals on Biomphalaria alexandrina snails and Oreochromis niloticus fish in Lake Burullus, Egypt.

Abstract

The quality of water in Lake Burullus was investigated to evaluate its effect on certain biochemical and histological aspects on Biomphalaria alexandrina snail and Oreochromis niloticus fish. The examined lake water quality criteria showed high levels of total dissolved solids (TDS), conductivity (EC), and levels of Pb and Fe. Sites that adjacent to point of discharging of waste waters showed higher levels of heavy metals and the least levels in dissolved oxygen (DO). The results showed that most of the examined biochemical parameters indicated affected liver (high levels in AST, ALP & TP and alteration in glucose & urea levels). Samples of Bahr Tera site in El-Hamoul center and Shakhloba site in Sidi-Salem were the most affected, while samples of Prempal site in Mottobus center were the least. Snails' histopathological examination showed degeneration, edema, hyper trophy and vaculation in head-foot muscles, degeneration and necrotic changes in the digestive gland, irregular shape in mature ova and reduction in sperm number in hermaphrodite gland. As well, fish histopathological investigation illustrated by necrotic change in most examined organs, the common features were: fiber splitting in muscles, cognation of blood vessels of gill filaments, vacuolar degeneration in liver and atrophy in glomeruli and epithelial cells of renal tubules in kidney. It was concluded that Lake Burullus water quality in wastewater discharge areas, adversely affects B. alexandrina snails and O. niloticus fish, and both can be used as bio-indicators for the presence of pollutants in their habitats.