Taxonomy of Finfish

2.1.1 Introduction

The nature of adipose eyelids, its development, extension of maxillae, position of nostrils, nature of operculum whether serrated or not, presence of pores around the mouth region and barbels, its numbers, type of mouth, the arching of lateral line, naked area of breast region, pigments, bands on the lateral side, etc., are to be studied carefully in large number of specimens covering different length groups.

Sometimes a morphological character attributed by a taxonomist as valid one for a species at a given length, may prove to be invalid at larger length groups or at smaller length groups. Hence, the taxonomists have to study the morphological characters at all length groups covering large number of specimens .

The colour pattern in most of the fishes changes after death. Ichthyotaxonomists should not give more importance to colouration. While studying colourations, the specimens available at fish markets must not be studied and the colour pattern will also change when the fish is preserved. Similarly the number of bands on the body, the spots and pigmentation have to be studied only in fresh specimens.