EVERYDAY SCIENCE

Detailed explanation-1: -Of the great diversity of primitive jawless fish, only two types of jawless fish survive today: hagfish (also known as slime eels, about 60 species) and lampreys.

Detailed explanation-2: -Yes. Lamprey and hagfish are both jawless fishes. They are the only living members of the taxonomical class Agnatha (Greek for “no jaws”).

Detailed explanation-3: -Answer and Explanation: The correct answer is (b) “hagfishes, lampreys". These fishes are commonly known of as “jawless fishes, and have kept their overall body shape, complete with a suction-like flat head instead of jaws for hundreds of millions of years. The jaws of sharks and rays evolved later.

Detailed explanation-4: -The oldest fossil agnathans appeared in the Cambrian, and two groups still survive today: the lampreys and the hagfish, comprising about 120 species in total.

Detailed explanation-5: -Hagfish are slime producing eels that live in marine environments. Lampreys are eels that are found both in freshwater as well as marine environments. No such alternate name. It is found in marine environments.