INTRODUCTION:
fishes are a well defined group of vertebrates.
they are the earliest known vertebrates which flourished during the Devonian , about 400million years ago . They form a successful group of animals comprising more than 40,000 species inhabiting all seas, rivers, lakes, canals, dams, muddy water, brackish water , estuaries and all places where there is water . they differ from each other in shape, size and habits, ranging from less than 2cms to 18metres. a very wide distribution of fishes into a variety of habitats has resulted in numerous adaptations in there morphology, physiology and behaviour.
fishes are a well defined group of vertebrates.
they are the earliest known vertebrates which flourished during the Devonian , about 400million years ago . They form a successful group of animals comprising more than 40,000 species inhabiting all seas, rivers, lakes, canals, dams, muddy water, brackish water , estuaries and all places where there is water . they differ from each other in shape, size and habits, ranging from less than 2cms to 18metres. a very wide distribution of fishes into a variety of habitats has resulted in numerous adaptations in there morphology, physiology and behaviour.
Defination:
fish is a cold blooded vertebrate, they have gills for respiration and have fins with fin rays and they can swim by the help of fins and body covered by scale.
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