H. S. Swingle

Experiments conducted from 1938 to 1941 indicated that large flathead catfish were predatory and in several cases eliminated the larger bluegiIls. In the 1962 experiments, 2- to 5-inch flatheads eliminated almost all the fathead minnows, while the larger flatheads (10") stocked in 1963 experiments apparently fed on larger bluegills in preference to fatheads. They eliminated all the large bluegills they could swallow except for a few in the 7-inch group and had left very few in the 4- to 6-inch groups. This apparently indicated a preference for larger fish as the flatheads increased in size...

Pond fertilization with N-P-K has been used in the Southeast for the past 20 years to increase fish production and to control aquatic weeds and mosquitoes. In ponds which had been fertilized previously for a IS-year period with N-P-K, no significant decrease in production resulted from omitting both nitrogen and potassium from the fertilizer mixture during a four-year ‘experimental period. It appeared that adequate nitrogen for plankton production became available from nitrogen fixation by bacteria or algae and from the organic matter and ammonium stored in the bottom muds. Omission of...

To facilitate the evaluation and use of population studies, reports should include: 1. A description of the area sampled, including the chemical classification and physical type of water, the type of bottom, depth of water, speed of movement and other information necessary to describe the environment from which the population came. 2. A description of the method of sampling employed in sufficient detail to enable the results to be evaluated and compared with results of other surveys. 3. Methods of measuring the results should be stated. The report should state if an attempt was...

Ponds stocked April 30 with 80 Tilapia mossambica per acre and drained October 16 produced in the 170-day experiment 1,480.9 pounds tilapia per acre in a fertilized pond and 3,224 pounds per acre where feeding was added. Tilapia (1- to 2-inch) stocked into ponds June 13 reached 5 to 8 inches in size in 126 days. A 2.6-acre pond was stocked April 18-20 with 80 brood tilapia per acre. The pond was fertilized and the fish fed. Tilapia hatching in this pond grew large enough to provide fishing by August 1. In the first 2-week period of fishing, the catch per acre was 1,222 fish weighing...