Question

How does class Agnatha (jawless fish) differ from class Osteichthyes (bony fish)?

1) Agnatha have no jaws while Osteichthyes have jaws
2) Agnatha have cartilaginous skeletons while Osteichthyes have bony skeletons
3) Agnatha have no paired fins while Osteichthyes have paired fins
4) Agnatha have no scales while Osteichthyes have scales

Answer 1

Class Agnatha, jawless fish, differ from class Osteichthyes, bony fish, by lacking jaws, paired fins, ossified skeletons, and scales.

Step-by-step explanation:

The class Agnatha, which includes jawless fish such as lampreys and hagfish, differs from Osteichthyes, or bony fish, in several ways. Firstly, as their name suggests, Agnatha lack jaws, unlike Osteichthyes, which have well-developed jaws. Secondly, the skeletal structure of Agnatha is not ossified; they do not have a bony skeleton as Osteichthyes do. Thirdly, Agnatha species lack paired fins, which are commonly found in bony fish. Lastly, Agnatha are without scales, whereas Osteichthyes generally have scales covering their bodies.