Fishes are the most primitive vertebrates from which all other vertebrates
including man has evolved. They are adapted to aquatic life with gills to
breathe and fins to move about, although a few species can move on land and
breathe air. They show a great diversity of form, habitat and are adapted to a
wide range of environment. Human race has been associated with fish life from
time immemorial. In the field of fisheries, conservation and utilization of fish
is important as fish is major food source harvested from natural populations.
Due to population explosion, high degree of pollution, urbanization,
industrialization and indiscriminate use of chemical fertilizer