Name four Chordata classes having cold blooded animals.

What do you mean by the term Osteichthyes?

How many chanbers are present in the heart of (a) Fishes (b) Frog?

Name the superclass of Chordata in which lateral line sense organs are found.

Identify the following fishes:

(a) Fish with 5 to 7 pairs of gills; (b) Fish with air bladder.