Fish Scales as a Bio Indicator of Environmental Pollution in Some Fish Species Collected from Different Areas in Saudi Arabia

The accumulation of heavy metals in different areas is an indicator of
toxicity. In this investigation, three fish species; namely, Scarus
pulchellus, Acanthopagrus bifasciatus, and Mugil cephalus were collected
from different regions in Saudi Arabia (Jeddah, Tabuk and Al-Jubail). Fish
diversity, environmental parameters and scale structure were addressed. For
the environmental parameters, some heavy metals (Zn, Mn, Cd and Cu)
were estimated in water samples collected from the studied areas. The light
microscopic structure of fish scale illustrated the shape of scale and
malformations, giving each species its characteristic taxonomical order. The
scales showed several deformities in shape and different scale structures
such as circuli, radii and focus. With respect to the three fish species, a
considerable variation in the morphology of their scales was observed in
specimens collected from different sites. Finally, this study revealed
important results showing the scale abnormalities as an important indicator
that differed with the heavy metal concentrations in different regions. The
result recommends setting a decision to prevent industrial and other
pollution which led to harmful changes in the tested fishes and subsequently
can cause serious effects on human health.