James W. Avault, Jr.

Polyculture studies were conducted in coastal brackish ponds evaluating buffalo (Ictiobus spp.) and channel catfish (Ictalurus punctatus) combinations. The 1973 and 1974 southwest Louisiana studies demonstrated feeding to be necessary, without it, buffalo were found to compete with catfish for natural foods. Bigmouth buffalo (I. cyprinellus), black buffalo (I. niger) and bigmouth x black hybrid buffalo when stocked at 100 per acre with 1,600 and 2,000 catfish did not compete to any extent for supplemental feed. Addition of buffalo in some ponds actually resulted in increased catfish...

Croaker, Micropogon undulatus, were stocked in 6 ponds in 1966 and again in 6 ponds in 1968 to determine general desirability for pond culture in brackish water. Growth and survival was low both years. In the fall, when ponds were drained, fish were about one year old; both males and females were ripe. Stomach analyses revealed that croaker preferred grass shrimp, Palaemonetes sp. (78.4 per cent occurrence) to fish (13.3 per cent occurrence). The condition index, using total length, was 1.36, while the length-weight relationship was log W =-5.2498 + (3.1652) (log L).

Antimycin was applied to five fresh-water ponds at 3, 4, or 5 ppb, and to two salt-water ponds !lit 10 ppb. Undesirable fish, including four centrarchids and one cyprinid, were eliminated from four of five freshwater ponds. Undesirable fish, including a centrarchid and a livebearer, were eliminated from both salt-water ponds. Mosquitofish, Gambusia affinis, were killed in five ponds, but were eliminated in none. Channel catfish, Ictalurus punctatu8, that were in four ponds, were not killed. Antimycin showed real promise as a fish toxicant particularly for removing trash fish from catfish...

Parasite-free snails of the genus Physa were experimentally infected with the miracidia of Posthodiplostomum minimum, the metacercariae of which were originally obtained from bluegills, Lepomis macrochirus. Twelve species of fish representing 5 families (Cyprinidae, Cichlidae, Centrarchidae, Poeciliidae and Ictaluridae) were exposed to cercariae from the infected snails. Two sunfish hybrids (female green sunfish, L. cyanellus X male redeal' sunfish, L. microlophus; and female bluegill X male redeal') were also exposed to cercariae of P. minimum. Only members of the family Centrarchidae...

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...