Page:British Reptiles, Amphibians, and Fresh-water Fishes.djvu/129

RIVER BULLHEAD can, and does, move quickly when occasion demands. It is a voracious feeder, and not only takes insects, shrimps, and worms, but will viciously attack and devour other fish at least its own size. The spines help it to impale, or stab, its victims. Spawning takes place in early Spring, when a depression made in the bed of the water serves as a nest. This the male jealously guards, and woe betide any invaders who approach too near the chosen territory. It has great tenacity, and will exist for some time out of its natural element. It should

also be mentioned that this species has the power of rapidly changing its colour if and when necessity arises. This happens, not only by reason of the change of environment, but also as a result of excitement on the part of the irate owner. The general colour is brownish, or yellowish-olive, on the upper parts, with black, or dark brown markings, some of which, by fusing together, form transverse bars. The underneath colour is yellowish- white, and most of the fins bear upon them dark spotted bars. The average length is 3 to 4 inches. 111