What is Cartilaginous Fish?

Cartilaginous fishes in the class Chondrichthyes. They fall under the superclass of Pisces. The characteristic feature of this class is the presence of a cartilaginous skeleton instead of a usual bony one. They lack swim bladders instead have large, oily livers for buoyancy. However, most of them depend on constant swimming to remain afloat. They have placoid scales which are small, hard dentine-like structures that help to remove water resistance during swimming.

Characteristics of Cartilaginous Fish

Some most common characteristic features of cartilaginous fishes are;

• Their skeleton is made of cartilage.
• They have small tooth-like placoid scales.
• They respire through gills.
• They lack swim bladders and instead have large, oily livers to maintain buoyancy.
• Some of the members are apex predators as well as scavengers.
• They show oviparity as well as viviparity.
• They have a specialized sensory organ called “ampullae of Lorenzini” that helps to detect any movement underwater.
• They mostly have a single dorsal and caudal fins, and a pair of pectoral and pelvic fins.
• Examples: Sharks (marine), Stingrays (marine & freshwater), Sawfish (marine), Manta rays (marine), Guitarfish (freshwater), etc.

The difference between bony fish and cartilaginous fish is the study of all the differences that make the two groups of fish separate. Bony fish and cartilaginous fish are two diverse groups of aquatic vertebrates. Bony fish and cartilaginous fish both share certain similarities like the presence of gills and fins. But bony fish and cartilaginous fish are fundamentally different, based on their skeletal structure.

Bony fishes have a bony skeletal system due to which they are called so whereas cartilaginous fishes have a skeletal system made of cartilage due to which the group derived its name. In this article, we will look into the general characteristics of bony and cartilaginous fishes and their characteristic differences and similarities.