There are six species of the black bass family. The two best known, because of their popularity among anglers, are the largemouth (Micropterus salmoides) and the smallmouth (Micropterus dolomieui).
These two species are very similar to one another. They were originally found only in the southern and central parts of the United States, but they've been introduced into most areas of the east and many areas of the west through stocking programs. The largemouth also been transplanted to many other parts of the world.
The largemouth black bass prefers rather quiet, weedy streams and lakes, while the smallmouth prefers running streams and clear, cool lakes. However, the species are often found together in the same habitat.
The largemouth grows to as much as 32 inches long and more than 22 pounds in weight. The smallmouth black bass averages about 20 inches in length and 6 pounds in weight, though it may reach sizes of 28 inches and more than 10 pounds.
Both species range from green to brownish or dark gray, even black. The largemouth is distinguished by a dark horizontal stripe. The smallmouth is usually mottled with darker colors over the background.
As the names suggest, the mouths are distinct in the two species. In the largemouth bass, the upper jawbone extends beyond the eye, while in the smallmouth it ends short of the eye.
All of the black bass are carnivorous, feeding primarily on smaller fish.
The largemouth is an aggressive predator that will attack almost anything smaller than itself if it moves. Its diet includes insects, frogs, snakes, and crayfish.
The diet of the smallmouth is similar, except it obviously tends to eat smaller prey, including many more insects than the largemouth bass.
Spawning for both species varies with geographical location, but generally takes place in May or June.
The male builds a nest on a firm bottom in relatively shallow water, then finds a female and urges her to the nest through repeated contact. She lays anywhere from 2,000 to well over 100,000 eggs, which are fertilized by the male.
A male may breed with more than one female, and a female may deposit eggs in several nests, each belonging to a different male.
After fertilization, the eggs become sticky and adhere to rocks or pebbles within the nest. The male guards the nest for several weeks while the young bass hatch out and begin to develop. While young, the fish school together, but they become more solitary as they mature.