The bowfin, a primitive freshwater fish, also known as the freshwater dogfish is a voracious fish.

Bowfin

The bowfin, a primitive freshwater fish, also known as the freshwater dogfish is a voracious fish.

A typical example of a spiny-rayed fish is the codfish.

Codfish

A typical example of a spiny-rayed fish is the codfish.

Flounder keep near the bottom, swimming on one side, and the two eyes are both on the side that is uppermost.

Flounder

Flounder keep near the bottom, swimming on one side, and the two eyes are both on the side that is uppermost.

The gar fish has a cylindrical body covered by rhomboidal bony scales that are coated with enamel, making a strong and complete armor.

Gar

The gar fish has a cylindrical body covered by rhomboidal bony scales that are coated with enamel, making…

In the lungfish, the development of the air bladder as a lung is much more complete than others in the same group.

Lungfish

In the lungfish, the development of the air bladder as a lung is much more complete than others in the…

The perch is typical of a large group of fishes, all of which have spiny rays. The perch is widely distributed in fresh-water lakes and streams.

Mackerel

The perch is typical of a large group of fishes, all of which have spiny rays. The perch is widely distributed…

External features of a perch.

Perch

External features of a perch.

digestive, excretory, and reproductive systems of a perch.

Perch

digestive, excretory, and reproductive systems of a perch.

Circulatory system of a perch.

Perch

Circulatory system of a perch.

"Arrangement of scales in the Roach (Leuciscus rutilus). L, Lateral line; t r, transverse line; a, transverse line from lateral line to yentral fin." — Encyclopedia Britannica, 1893

Roach Scale Arrangement

"Arrangement of scales in the Roach (Leuciscus rutilus). L, Lateral line; t r, transverse line; a, transverse…

The salmon is well known both from its commercial importance and from its remarkable migrations up rivers to spawn.

Salmon

The salmon is well known both from its commercial importance and from its remarkable migrations up rivers…

"Cycloid scale from the lateral line of Odax linealus." — Encyclopedia Britannica, 1893

Scale

"Cycloid scale from the lateral line of Odax linealus." — Encyclopedia Britannica, 1893

Common skate (ray). The skates and rays have a broad body, partly due to the merging of the body into the large, horizontally flattened pectoral fins.

Skate

Common skate (ray). The skates and rays have a broad body, partly due to the merging of the body into…

The jaws and teeth of the common skate (ray).

Skate

The jaws and teeth of the common skate (ray).

Mouth and gill slits of the common skate (ray).

Skate

Mouth and gill slits of the common skate (ray).

the sturgeon has a cylindrical body covered by rhomboidal bony scales that are coated with enamel, making a strong and complete armor.

Sturgeon

the sturgeon has a cylindrical body covered by rhomboidal bony scales that are coated with enamel, making…