Heavy Metals Toxicity
and Bioaccumulation Patterns in the Body Organs of Four Fresh Water
Fish Species
Safina Kousar* and
Muhammad Javed
Department of Zoology
and Fisheries, University of Agriculture, Faisalabad- 38040,
Pakistan *Corresponding author: safinazoologist@gmail.com
Abstract
Various environmental pollutants, including metals can cause toxicological
effects on aquatic animals especially fish species. Laboratory experiments were
conducted to determine acute toxicity and bioaccumulation patterns of arsenic
(As), nickel (Ni) and zinc (Zn) in 150-day old fish species (Labeo rohita,
Cirrhina mrigala, Catla catla and Ctenopharyngodon idella),
separately, in glass aquaria under constant water temperature (30oC),
total hardness (300 mg L-1) and pH (7.5). Catla catla showed
significantly (P<0.05) highest
sensitivity to metals while L. rohita
was least sensitive.
Significantly variable accumulation of metals was observed in fish that followed
the order: Zn>Ni>As. Among exposed fish species, Cirrhina mrigala
exhibited significantly higher ability to amass Ni (146.8±149.1 μg g-1)
and Zn (243.0±190.5 μg g-1), followed by Ctenopharyngodon idella,
Labeo rohita and Catla catla at 96-h LC50. Liver showed
higher tendency to accumulate Ni, followed by gills and kidney with significant
differences while kidney showed higher tendency to accumulate As, followed by
liver. Fins and scales exhibited significantly
(P<0.05) least tendency to
accumulate all the three metals. Accumulation of metals in different fish
species is the function of their membrane permeability, which is highly species
specific. Due to this reason different fish species showed different amount of
metal accumulated in their bodies. This study also reveals that the metals,
being conservative in nature have higher ability of biomagnifications.