Question

Identify a fish that breathes through its lungs
A. Lungfish
B. Rohu
C. Dogfish
D. Stingray

Answer 1

Hint: The main organ for respiration in the fishes is the gills. But there are certain species of fishes that breathe through their lungs too. Such types of fishes possess both gills as well as lungs. Thus they can breathe in air as well as inside water.

Complete answer:
To solve the given question, we must know about the process of respiration and the organs of respiration in fishes.
We all know that fishes breathe through gills. But there are some fish that breathe through lungs. One such example is the lungfish.
In lungfish, the lungs are connected to the larynx and the pharynx. It has a vascularized gas bladder. Most lungfishes have two lungs but the Australian lungfish has only one. The lung is divided into very small air sacs. These small air sacs increase the surface area so as to make the respiration efficient.

Therefore the correct answer to this question is Lungfish.

Additional information-
> Rohu is a freshwater fish. It is an edible fish. The fish is herbivores but in earlier stages, it is carnivorous.
> Dogfish is a surface feeder. It has homodont teeth. It is viviparous.

Note:
In the above answer it must be noted that lungfish uses its gills also at times while breathing in air. The deoxygenated blood passes through the gills before reaching the lungs. The carbon dioxide is soluble in water and so much of the blood gets purified inside the gills.