Which one of the following pairs of animals comprises 'Jawless fishes' ?
Which one of the following pairs of animals comprises 'Jawless fishes' ?
Guppies and hag fishes
Lampreys and eels
Mackerals and Rohu
Lampreys and hag fishes
Solution
Jawless fishes (Agnatha) include animals that lack jaws, and both lampreys and hag fishes belong to this group.
Lampreys: They are parasitic or scavengers and have a toothed, sucker-like mouth but lack true jaws.
Hag fishes: They are scavengers and have a primitive, jawless mouth.
Other pairs:
Guppies and hag fishes: Guppies are bony fishes (with jaws), not jawless.
Lampreys and eels: Eels are jawed fishes (ray-finned or other types of bony fishes).
Mackerels and Rohu: Both are bony fishes (jawed fishes).
Thus, Lampreys and hag fishes are the correct pair of jawless fishes.