List five characterstic features of fishes.

Explanation

(i) Fishes are poikilothermic, whose internal temperatures varies, considerably.
(ii) The body has a covering of scales.
(iii) Body muscles are arranged into segments called myotomes.
(iv) The body is differentiated into head, trunk and tail.
(v) Respiration is done by 5 to 7 pairs of gills, which are covered by an operculum or sometimes may be naked.