Question

what is fish gills explain​

Answer 1

$\huge\boxed{\fcolorbox{lime}{yellow}{⭐About fish gills⤵࿐}}$

Fish gills are organs that allow fish to breathe underwater. ... In some fish, capillary blood flows in the opposite direction to the water, causing counter-current exchange. The gills push the oxygen-poor water out through openings in the sides of the pharynx.

Answer 2

Most fish exchange gases using gills on either side of the pharynx (throat). Gills are tissues which consist of threadlike structures called filaments. These filaments have many functions and "are involved in ion and water transfer as well as oxygen, carbon dioxide, acid and ammonia exchange