What makes cartilaginous fishes unique?

What makes cartilaginous fishes unique?

The cartilaginous fish are jawed fish with paired fins, paired nostrils, scales, two-chambered hearts, and skeletons made of cartilage rather than bone.

How cartilaginous fishes differ from bony fishes?

Technically, the most obvious disparity between bony vs cartilaginous fish comes from the fact that the skeleton of bony fish is made of bones alone, while that of cartilaginous fish is made of cartilage. There are more than 20,000 fish species in the world. Of the class Chordata, Pisces is a super class.

What makes sharks different from other fish?

But how is a shark different from other kinds of fish? A shark’s skeleton is made of cartilage, a type of strong but flexible tissue. Most other fish are covered in smooth, flat scales. A shark is covered in sharp, toothlike scales called denticles.

Why are cartilaginous fish important?

Cartilaginous fishes have to be viewed as an integral part of any ecosystem since in most instances they are among the top predators. Even among cartilaginous fishes there exists a hierarchy with some species being prey to others.

Which fish is cartilaginous fish?

Cartilaginous fish are fish that have a skeleton made of cartilage, rather than bone. All sharks, skates, and rays (e.g., the southern stingray) are cartilaginous fish. These fish all fall into the group of fish called the elasmobranchs.

Do cartilaginous fish have gills?

Cartilaginous means that the fish’s skeleton is not made of bones. For most cartilaginous fish, they have five or more gill slits that open directly into the water. They rely on something called “ram ventilation” to push water through their gills.

Are cartilaginous fishes viviparous?

Unlike most bony fishes, all chondrichthyans have internal fertilization. Reproduction can be oviparous (laying eggs, notably the “mermaid’s purses” found on beaches), viviparous (live-bearing), or ovoviviparous (eggs carried within the mother).

Do cartilaginous fish have jaws?

Cartilaginous Fish Cartilaginous fishes have a skeleton made of cartilage, a material that is lighter and more flexible than bone. These type of fishes have movable jaws that are usually armed with well developed teeth. The mouth is often located underneath the head.

How does a shark differ from most freshwater fish?

While most fish have gills tucked behind a bony flap called an operculum, sharks exhale water through gill slits located behind their head. A shark’s skin is covered with tiny dermal denticles that differ from scales on most fish.

Which fish is cartilaginous?

Cartilaginous fishes (chondrichthyes) represent the oldest surviving jawed vertebrates and, as the name suggests, have a skeleton made out of cartilage. They include sharks, rays, and skates (elasmobranchii) and chimeras (holocephali).

How do dermal denticles differ from other scales?

Like our teeth, dermal denticles have an inner core of pulp (made up of connective tissues, blood vessels, and nerves), covered by a layer of dentine (hard calcareous material). While scales in bony fish grow as the fish gets large, dermal denticles stop growing after they reach a certain size.