Shark anatomy

Shark Anatomy refers to the physical structure and biological systems of sharks, a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head.

External Anatomy

The external anatomy of sharks is defined by several unique characteristics.

Skin

The skin of a shark is made up of a complex dermal corset made of flexible collagenous fibers and arranged as a helical network surrounding the body. The skin is covered in placoid scales, also known as dermal denticles, which provide a hydrodynamic advantage as the shark moves through water.

Fins

Sharks have several types of fins, including dorsal fins, pectoral fins, pelvic fins, and a caudal fin. The dorsal fin provides stability while swimming. Pectoral fins assist with steering and lift. Pelvic fins aid in stabilization, and the caudal fin propels the shark forward.

Teeth

Shark teeth are embedded in the gums rather than directly affixed to the jaw, and are constantly replaced throughout the shark's life. The shape and size of shark teeth vary according to the shark's diet.

Internal Anatomy

The internal anatomy of sharks includes the skeletal system, digestive system, respiratory system, circulatory system, and sensory systems.

Skeletal System

Unlike most fish, sharks have a completely cartilaginous skeleton. This reduces the shark's weight and provides additional flexibility.

Digestive System

The digestive system of a shark includes the mouth, teeth, jaws, esophagus, stomach, intestines, and cloaca. Sharks have a U-shaped stomach that is capable of distending to accommodate large meals.

Respiratory System

Sharks breathe through a series of five to seven gill slits located on either side of their bodies. Water flows over the gills as the shark swims, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled in a process known as respiration.

Circulatory System

Sharks have a two-chambered heart and a circulatory system that functions on the principle of single circulation, with the blood passing through the heart only once during each trip around the body.

Sensory Systems

Sharks have highly developed sensory systems, including sight, smell, taste, hearing, touch, and electroreception. The latter allows them to detect the electric fields produced by other animals, aiding in hunting and navigation.

See Also

• Fish anatomy
• Cartilaginous fish
• Shark behavior

References

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