Taxonomy of Finfish (1+2)

2.1.5.3 Mouth

Mouth is the chief organ for feeding of the fish and based on the type of food it takes, the shape, position, size and form vary. In most cases it is terminal or slightly below sub-terminal (Fig. 14B). Surface swimmers as Danio, Puntius, and Rasbora species have a terminal mouth (Fig. 14A). On the other hand hill stream fishes as ,) Balitora, Bhavania, Garra specieshave their mouth narrow and placed in the ventral side of the snout (Fig. 14 C) to suit their scratching of food from the rocks and boulders where they live without being washed away by the surging waters. Species of Glyptothorax have their mouth placed slightly inferior. In Belonidae (freshwaterGars) the mouth is superior (Fig. 14 D), wide and the cleft extends to the border of the eyes (orbit). 

Fig.14. Shape of mouth. A. Terminal (Danio, Rasbora, Putius). B. Sub-terminal. C. Inferior (Balitora, Garra) D. Superior (Belontids).