question_answer 64)

  Endoskeleton of fishes are made up of cartilage and bone, classify the following fishes as cartilaginous or bony Torpedo,             Sting ray.             Dog fish, Rohu,                    Angler fish,         Exocoetus.

Answer:

             

Bony fishes	Cartilagirsous fishes
1.  Endoskeleton is bony	Endoskeleton is cartilaginous
2.  Four pairs or gill slits are present which are covered by an operculum.	5-7 pairs of gill slits are present and an operculum 's absent
3. Mouth is terminal is position.	Mouth is ventral in position.
4.  Caudal fin is homocercal.	Caudal fin is heterocercal
5.  Air or swim bladder is usually present.	Air or swim bladder is absent.
6.  Marine and freshwater	Exclusively marine fishes Most or them are viviparous
7. Mostly oviparous. e. g., Labeo rohita. (rohu), Angler fish, fish, exocoetus	e.g., Scoliodon. (dog, fish), Torpedo, sting ray.)