MP Board notes-Respiration
Respiration in fishes(by gills) Fishes specially bony fishes have internal gills.Gills are protected by external bony plate called operculum.Under the operculum chamber,gill pouches are present which maintains the flown of water in gill pouch and thus gills remain in contact with water.Gills are arranged in row,a comb like structure called gill filaments.Gill filaments are are raised into no. of horizontal flat folds called gill lamellae which are richly supplied with blood capillaries.Here exchange of CO 2 and O 2 takes place by diffusion through blood.