Wednesday, May 10, 2006


Cartilaginous fish includes species like shark, skates and rays. Sharks are the latest hunters’ of the oceans. Shark is big and fast. Because they have very strong teeth, it is easy for shark to break pray. Rays and Skates are more quiet or non-aggressive. Rays and Skates bodies are large. They have wings and tails. Wings help them to move smoothly through the water and they use tail as a wheel. Rays and Skates are bottom feeders. Cartilage is a type of dense connective tissues, and it is also have cells which composed of Chondrocytes, and the fibres which composed of Collagen and Elastic fibres, and Matrix which composed of Proteoglycans

Cartilage has strong jaws and their mouth is on the underside of the body. The eyes of cartilage are on top of the body. They can not see food as it enters their mouth. Some Shark solve this problem by touching their food with their nose first.
Some use powerful electro sensory system. Sharks, Skates and rays have rough skin. Sharks have 5 to 7 gills slits on each side of their head. Where as Bony fish have 1 gill on each side. Chimaeras or Gost sharks’ skins are smooth and have only one pairs of external gill openings. Cartilage fish give live birth and Bony fish produce eggs. Cartilage fish live in only salt water and bony fish live in all types of water.

Bony fish have hard cartilage for skeleton. The bony fish are classified into Lobe finned and the Ray –finned. Lobe-finned bone fish includes fish such as lungfish and coelacanth’s, where as Ray-fins includes the goldfish, tuna, and trout.
Bony fish are true fish, such as snapper, groper and gurnard. They have a bony skeleton and single pairs of external gill openings. The mouth is generally at the front of the body and they have a tail fin, with the top and bottom portions nearly the same size. It has relatively short tube. Bony fish reproduce by external fertilisation of eggs and releases them into water. The male releases sperm called Milt into water. Then Milt fertilise eggs
Bony fish is a fish with a skeletal system that is made out of cartilage. Their liver is filled with oils which keep them from sinking. They have internal fertilisation.

The bones of fish are made mostly by calcium but Shark does not have any bones. Shark skeleton is made of cartilage, and have no bladder, but bony fish have a gas filled swim bladder which enables them to float in the water. Bony fish have movable parts were as shark does not have. Shark can turn around in a smaller space than bony fish.

On top of shark it is dark in colour which is called dorsal side, and light colour on the bottom which is called ventral. Shark have noses that use for smelling, not for breathing one can find their pairs of nostrils on underside of their snouts. The eyeball of shaka is cornea, iris, pupils, lens and retina. Shark teeth are parallel.


Studios, A.R. 1997-2006 Biology for kids’ vertebrates’ fish [Online].Available from:[2006, May 09 13:00]


Post a Comment

<< Home