The color of all trout varies with environment. In general, the rainbow is silvery on the sides and belly, with bluish-green on the back. A generous sprinkling of black spots appear along the back, and on the dorsal, adipose and caudal fins. A pinkish band usually extends along the sides. Rainbows lack teeth on the back of the tongue, while also having short heads. The lip bone on the upper jaw seldom extending beyond the hind margin of the eye. Lengths of 3 feet 9 inches and weights of 42 pounds have been recorded.
Rainbows usually spawn during the early spring months, although fall spawners are used in most hatcheries. The number of eggs produced varies with the size of the fish. A 10 to 12-inch rainbow produces from 800 to 1,000 eggs, while a fish over 24 inches may produce from 5,000 to 9,000 eggs.
