Question

Write the difference between chondrichthyes and osteichthyes

Answer 1

Cartilaginous fishes (Chondrichthyes)

Examples:Sharks, rays and Skates 
1. Cartilaginous endoskeleton. 
2. Gills are exposed to the outside. 
3. Mouth on the ventral side of the head. 
4. Swim bladder absent. 
5. Placoid scales. 
6. Fertilization is internal. 


Bony fishes (Osteichthyes) fishes 
Examples: Salmon, Flying fish, Sea horse, Rohu, trout 

1. Bony endoskeleton. 
2. Gills covered by operculum. 
3. Mouth at terminal end of the head. 
4. Swim bladder present. 
5. Cycloid and ctenoid scales. 
6. Fertilization is external

Answer 2

The difference between Chondrichithyes & Osteichthyes are:

Chondrichithyes:

E.g - Sharks , ray's, skates

1. Mostly marine with a heterocereal tail.

2. Endoskeleton cartilagenous.

3. Skin with placoid scale.

4. Gills 5-7 pairs & exposed to outside

5. Swim bladder is absent.

6. Fertilization is internal.


Osteichthyes:

E.g- Rohu, Sea horse, Salmon

1. Developed bony fish with homocereal tail.

2. Endoskeleton bony.

3. Skin with mucosglands, ganoid, cycloid & ctenoid scales.

4. Gills four pairs with opercula.

5. Swim bladder present.

6. Fertilization is external.