Q.
Cartilaginous fishes have
(1) placoid scales
(2) cycloid or ctenoid scales
(3) scroll valve
(4) operculum
Solution:
Characteristic
Cartilagenous fish
a
Habitat
Mostly marine
b
Caudal fin
Heterocercal
c
Mouth
Ventral
d
Gill opening
Usually 5 pairs, no operculum
e
Exoskeleton
Placoid scales
f
Endoskeleton
Cartilaginous
g
Intestine
With scroll valve
h
Air bladder
Absent
| Characteristic | Cartilagenous fish | ||
|---|---|---|---|
| a | Habitat | Mostly marine | |
| b | Caudal fin | Heterocercal | |
| c | Mouth | Ventral | |
| d | Gill opening | Usually 5 pairs, no operculum | |
| e | Exoskeleton | Placoid scales | |
| f | Endoskeleton | Cartilaginous | |
| g | Intestine | With scroll valve | |
| h | Air bladder | Absent | |