Question

Fishes belonging to dipnoi are commonly called-------------.
A) Lung fishes
B) Mud puppies
C) Flying fishes
D) Globe fishes

Answer 1

Hint: Dipnoi is a subclass of fishes. The species belonging to this class have modified swim bladders. Several species belonging to this group are extinct.

Complete Answer:
To answer this question, we must know about the characteristic features of subclass Dipnoi.
The Dipnoi are the group of sarcopterygian fish. This group consists of several fishes which are living as well as other fishes which are extinct.
The word Dipnoi means Di=double and pnoe means breath. So the word Dipnoi means double breather. It is the class of bony fishes which resembles teleosts as well as amphibians.

The Key characteristics of Dipnoi are:
- They have lungs which are used for breathing.
- They have a three chambered heart.
- They do not have teeth but have crushing tooth plates.
- They have a single dorsal fin.
- Notochord is unconstructed.
- They have well-developed internal skeletons.

1) Example of Dipnoi fishes is the lungfish. They have a highly specialised respiratory system. Their lungs are connected to the larynx and pharynx without a trachea. The lungs in the lungfishes have numerous air sacs. These air sacs increase the surface area for gaseous exchange.
2) Mud puppies- It is a species of salamander. They have lungs, external gills for respiration.
3) Flying fishes- They are the fishes which have fins modified for flying. They fly to escape from predators. They do not have any specific organ for breathing in air.
4) Globe fishes- These are the fishes which can inflate itself.

The correct answer is (A) Lung fishes belong to subclass Dipnoi.

Note: Lungfish are freshwater fishes. They have the ability to breathe air. Lungfish has lobed fins with a well developed skeletal system.