Ray Allison

Biological Control of a Trematode Parasite of Bluegill

An investigation was begun July 1, 1962 to determine the potential of snails infected with cercariae of Posthodiplostomum minimum to produce infection in bluegills, Lepomis macrochirus. Infected snails, in aluminum wire baskets, were stocked into plastic-lined pools at rates of 1 or 5 per pool. Bluegills of 2 sizes, 1-inch or 3-inch, were stocked into the pools. All bluegills were exposed to cercariae for 24 days at which time the experiment was terminated. One month later counts were made of the parasites found in each fish. One-inch bluegills contained an average of 20 parasites per fish...

Parasite Epidemics Affecting Channel Catfish

The prevalence of parasitic epidemics is dependant, to a large extent, upon the density of the host population. Through the application of recent research, up to 2,400 pounds of channel catfish can be produced per acre of water, thus placing their commercial culture on a basis comparable to production of other farm animals. Since fish are confined to a limited environment in ponds without flowing water, they are surrounded by their own metabolic wastes throughout the production period. Such an environment is ideal for the propagation and development of parasitic populations. The great...