Which one of the following pairs of animals comprises ‘jawless fishes’?

Options

(a) Mackerals and Rohu
(b) Lampreys and hag fishes
(c) Guppies and hag fishes
(d) Lampreys and eels

Correct Answer:

Lampreys and hag fishes

Explanation:

Lampreys and hagfishes are unusual, jawless fish that comprise the order Cyclostomata, so named because of the circular shape of the mouth. The brains of lampreys and hagfishes differ a lot, but they also show a large number of similarities, as do all craniate brains.