Taxonomy of Finfish

3.1.2 Marine Finfish taxonomy

Finfish taxonomy is the only subject in ichthyology which deals with populations, species and higher taxa. No other branch in fisheries science occupies itself in a similar manner with this level of integration in the organic world. The contribution of finfish taxonomy to fisheries science has been both direct and indirect. For conservation and management of our fishery resources the identification of finfishes is vital. Ichthyotaxonomical study reveals numerous interesting evolutionary phenomena in piscine phylogeny and the study is most indispensable for culturing fish fauna. The correct identification of a particular candidate finfish for aquaculture is very important for successful culture practices. On the whole taxonomic study on finfishes furnishes the urgently needed information about species and it cultivates a way of thinking and approaching of all biological problems which are much needed for the balance and well being of fish biology as a whole.

Pisces are the most numerous, highly diversified groups exhibiting enormous diversity in their morphology, in the habitats they occupy and in their biology. Fishes constitute almost half the total number of vertebrates (Nelson, 1976). According to Cochen (1970), the estimated number of fishes is about 20,000 - 22,000 and Nelson’s (1976) estimate is 18,818 living fishes. Fishes can be simply defined as aquatic poikilothermic vertebrates and have gills throughout their life span and limbs if any in the shape of fins. Most fishes fall into one of six broad categories. They are rover-predator, lie-in-wait predator, surface-oriented fish, bottom fish, deep bodied fish and eel like fish. Thus their ecological diversity is reflected in variety of body shapes and means of locomotion they possess. The modern living fishes could be broadly classified into two categories namely, elasmobranchs and teleosts.