School Shark The school shark is a small, shallow-bodied shark with an elongated snout. The largemouth is crescent-shaped and the teeth are of a similar size and shape in both jaws. School sharks are dark bluish grey on their upper (dorsal) surfaces and white on their bellies (ventral surface). The snout is much longer than the average shark. The pectoral fin, which is one of the most pronounced characteristics of sharks, has a rounded form and does not extend beyond the head in adults (in juveniles it extends past the gills).
This species differs from similar species such as catsharks in that its caudal fin is slightly asymmetrical and the upper lobe is longer than the lower. The fish averages about 10 inches in length but is as long as 18.5 inches, or 1 foot. The average weight of a school shark is 0.25 pounds, but it can weigh up to 0.75 pounds.
There are no known distinguishing marks on the exterior of the shark. The inside of its mouth is also colored blue, grayish-brown, or black.
The external characteristics are very similar to other sharks in this family (e.g., catsharks). The difference lies in the following internal traits: dentition, caudal fin shape, and color patterns found inside the mouth.
All sharks have five to seven-gill slits on each side of their body. The first is located over the eyes, then there are two that are close together at the top of the head and then one on each side beneath these first ones. Each slit has two externally opening holes running vertically through it which carry water in and out of the fish. The school shark has three to five rows curved in an S-shape that contain 72-78 teeth on each jaw.
These sharks are also dull grey-blue in color, merging with the murky depths in which they tend to hide. Their bellies are stark white, accenting their dark backs. They have a slim snout that is much longer than average, giving them an elongated appearance.
The habitat of the school shark is in temperate waters throughout the world seas. They are found in coastal areas and on continental shelves, near rocks and seaweed beds, at depths ranging between 330 feet to 3100 feet. They live in either small schools or alone. When they are alone they tend to hang out in crevices of reefs or caves, which is where they got their nickname "rockfish." They live most of their lives here, only venturing out at night when they go hunting for food.
School sharks eat weed-like seaweeds like kelp and algal matter that grow on the rocky seafloor. They prefer to eat at dusk and after dark, as they are nocturnal hunters.
The school shark has been reported in every ocean of the world, with a distribution that extends from polar waters southward to temperate regions and into subtropical areas. In general, these sharks have distribution in temperate and cool waters of the Northern hemisphere.