Natural History of Pimephales Vigilax (Cyprinidae)

Abstract

Food use, breeding and non-breeding behavior, and scales of this fresh-water fish were studied. These fish are sedentary bottom-dwellers, preferring quiet waters. They are omnivorous, preferring small arthropod larvae. They school in the daytime but not at night or during breeding periods. During the summer, the male chooses the nest site under bottom debris such as stone or wood. He enlarges a burrow and defends it before and after spawning. Details of behavior and scale- form are given. Pimephales vigilax (Baird and Girard) is important commercially as a bait species and constitutes a large portion of the food of com- mercial and game fishes. No literature dealing specifically with its life history was found. My studies concerned the food used, feeding habits, general behavior, breeding habits, and scale profile. Studies were made in the laboratory and in a small pond 5 miles north of Oklahoma State University cam- pus during 1960 and 1961. Specimens were collected with fine-mesh seine from Lake Texoma, taken to the laboratory at Stillwater, placed in metal aquaria, and treated with terramycin and acriflavine to pre- vent bacterial infections. Thirty-five specimens were transferred to aquaria for observation, and 400 were placed in a suitable farm pond 5 miles north of the laboratory. The capacity of the aquaria varied from 20 to 30 gal. Sand and rock were placed in tank No. 1, aquatic plants and small gravel were placed in No. 2, but none of these in the others. Snails (Helisoma) were kept in all aquaria to remove excess scum. The aquaria were provided with the following fish: Nos. 1 and 2, 6 males and 7 females each at the beginning for behavior studies (later, the first were removed and one male and two females replaced) and Nos. 3 and 4, one male and one female each. Thereafter, when a fish was removed from an aquarium because of illness or death it was replaced with one from the farm pond. The tanks were aerated liber- ally. White worms were used as one of the foods for the minnows. Small nematodes were reared as described by Emmons (1952) and fed to the young fish. Ground shrimp, cultured Daphnia, poultry laying mash, stock food (500% protein meal), chopped and whole earthworms, June bug larvae and mosquito larvae, were also used. For stomach-analysis 40 fish were collected from the farm pond in