Question

Which of the following is an example of lung fish?
A) Exocetus
B) Lepidosiren
C) Clarius
D) Pristis

Answer 1

Hint: Lungfish, belongs to subclass Dipnoi, any member of a group of six species of living air-breathing fishes and several extinct relatives belonging to the class Sarcopterygii and characterized by the possession of either one or two lungs.

Complete answer:
The lung of the lungfish (Protopterus aethiopicus) is paired, long and cylindrical. It is situated on the dorsal aspect of the coelomic cavity ventral to the ribs. Much of the gas exchange tissue is found in the proximal aspect of the lung with the caudal part largely taken up by a centrally situated air-duct with a few large peripherally located alveoli. Interalveolar septa, arranged at different hierarchical levels from the air-duct, subdivide the lung into alveoli, the gas exchange compartments. Lungfish us a freshwater fish. It belongs to the subclass Dipnoi. It has powerful, long snakelike or eellike bodies. It can breathe in water having low oxygen with the help of well-developed lungs. The lungs have a modified swim bladder. An example of lungfish includes Lepidosiren paradox. It is an American lungfish found in swamps and slow-moving waters of the Amazon.

Hence, the correct answer is option (B)

Note: The slim, eel-like African protopteridae fishes and the even slimmer South American Lepidosiren paradoxa have long, stringy, very mobile pectoral and pelvic fins that are in a constant state of agitation—touching and sensing surroundings.