Question

how do crocodile and dolphin respire . what is the scientific name of that respiration

Answer 1

dolphins are no fishes, they are also mammals. so they breathe through lungs. they cannot stay underwater for a long time. they have to come on the surface to breathe.
crocodiles posses lungs and breathe air.
Ichthyosaur is the scientific name.

Answer 2

crocodile and dolphin have good respiratory system
they can live in water 1 to 2 hrs without taking breath