Biology of Fishes

Science

Fishes that have skeletons primarily composed of bone tissue

Bony fishes

Fishes that have skeletons primarily composed of bone tissue. Bony fishes. Bony fishes are a type of fish with skeletons made mostly of hard bone instead of cartilage, helping them swim and survive in different water environments.

A strong, flexible connective tissue found in skeletons

Cartilage explained in an easy to understand way.

Cartilage

A strong, flexible connective tissue found in skeletons. Cartilage is a rubbery, cushioning tissue in our joints that helps our bones move smoothly.

Fishes that have skeletons made of cartilage

Cartilaginous fishes

Fishes that have skeletons made of cartilage. Cartilaginous fishes. Cartilaginous fishes, like sharks and rays, have skeletons made of flexible cartilage instead of hard bone.

The tail fin, it is used for propulsion

Caudal fin

The tail fin, it is used for propulsion. Caudal fin. The caudal fin is the tail of a fish that helps it move through water.

The back, or upper side of an organism

Dorsal

The back, or upper side of an organism. dorsal. In simple terms, "dorsal" refers to the back side of an animal or organism.

A fin located on the back of most marine and freshwater vertebrates

Dorsal fin

A fin located on the back of most marine and freshwater vertebrates. Dorsal fin. It helps fish and other aquatic animals to stay stable and steer while swimming.

The sensory receptors that fish use to detect movement and vibrations in the water

Lateral line system

The sensory receptors that fish use to detect movement and vibrations in the water lateral line system. The lateral line system is a network of tiny hairs along a fish's body that helps it sense changes in the water around it.

The hard flap that covers and protects a fish’s gills

Operculum

The hard flap that covers and protects a fishs gills. Operculum. The operculum is a bony structure that acts like a shield, allowing fish to breathe by covering their delicate gills.

Fins located on each side, usually kept folded just behind the operculum

Pectoral fin

Fins located on each side, usually kept folded just behind the operculum. Pectoral fin. In simple terms, a pectoral fin is a fish's side fin that helps it steer and balance in water.

A small hole behind each eye that opens to the mouth in some fish

Spiracle in fish

A small hole behind each eye that opens to the mouth in some fish. Spiracle in fish. Spiracles are openings that help some fish breathe by allowing water to pass to their gills even when their mouth is closed.

a gas-filled sac in bony fishes that helps them to control their swim depth

Swim bladder explained in an easy to understand way.

Swim bladder

A gas-filled sac in bony fishes that helps them to control their swim depth. Swim bladder. The swim bladder is an organ in fish that helps them float at different depths in water.

The front, or lower side, of an organism

Ventral

The front, or lower side, of an organism. Ventral. In simple terms, ventral refers to the belly or front side of an animal's body.