Question

What are the two groups of fish?

Answer 1

Fishes:

1. Fish are aquatic vertebrates having gills and fins.
2. Fish have an elongated body covered with scales.
3. Fish belong to the phylum Chordata.
4. Two groups of fish are- Agnatha and Gnathostome.

Two groups of fish:

Agnatha:

1. The first vertebrates were likely members of the agnatha class.
2. The fish in this class lack paired fins and a stomach.
3. These are jawless fish.
4. Example: Lampreys, Hagfish.

Gnathostome:

1. All jawed vertebrates fall into the infraphylum Gnathostomata, which includes the two categories, Chondrichthyes and Osteichthyes.
2. Gnathostomata have paired and occasionally jointed appendages.
3. Ninety-nine percent of all extant vertebrates are members of the 60,000+ species-strong gnathostome variety.
4. Chondrichthyes: These are cartilaginous fish. Example: Dogfish, Whale shark.
5. Osteichthyes: These are bony fish having jaws. Example: Lungfish, Salmon