What are the organs used to breath in bony fish, amphibians, reptiles, birds and mammals?

Answer 1

bony fish - gills
amphibians - some have gills when they are immature (like the tadpoles of frogs and toads) and develop lungs as adults; others keep their gills throughout their lives
reptiles - lungs
birds - lungs
mammals - lungs

Answer 2

To address fish specifically...

Fish achieve gas exchange in a number of different ways. They can exchange oxygen and carbon dioxide (along with other metabolites like ammonia) with water through their gills. There is also minimal interaction through the skin of a fish. All fish also have a gas bladder (secondarily absent in some groups) that may interact with the gut tract. In fish that do have a direct connection, called physostomes (which are generally more basal lineages, more derived lineages see the connection interrupted at some point during development), gas may be exchanged with air at the surface by gulping and swallowing the air. In some fish (i.e. lungfish) the bladder is so specialized that it functions like a lung with a highly vascularized membrane. Many fish have this ability including gar, sturgeon, tarpon, etc. Some fish also have a vascularized tissue in their buccal cavity (mouth) that facilitates gas exchange with air and some species have a vascularized stomach that permits gas exchange.

In amphibians, gas exchange is achieved through lungs and secondarily through the skin. The porous skin of amphibians is the reason they are so susceptible to pollutants.

Reptiles, birds, and mammals all have lungs to facilitate gas exchange.

Answer 3

fish have gills, the rest have lungs

Answer 4

uhhh idk..lungs or gills.