John B. Gratzek

Protection of channel catfish (Ictalurus punctatus) against Ichthyophthirius multifiliis (Fouquet) by immunization with varying doses of Tetrahymena pyriformis (Lwoff) cilia

Abstract Channel catfish, Ictalurus punctatus , were immunized with varying doses of Tetrahymena pyriformis ciliary antigen, and challenged with Ichthyophthirius multifiliis . Results indicated that two doses of either 5 μg or 25 μg of T. pyriformis ciliary antigen conferred a high degree of protection against challenge with I. multifiliis . Only 3.1% (5 μg dose) and 2.8% (5 μg dose) of the fish in these groups developed clinical disease resulting in death. Two doses of either 10 μg or 2.5 μg of antigen produced a significant but not acceptable degree of protection, while 1.0 μg of antigen produced no protection.

In vitro demonstration of serological cross-reactivity between Ichthyphthirius multifiliis foquet and Tetrahymena pyriformis lwoff

Abstract The antigenic relation between Tetrahymena pyriformis (Ehrenberg, 1830) Lwoff 1947 and Icthyophthirius multifiliis Fouquet 1876 was investigated using various in vitro immunologic tests. Tomites of I. multifiliis exposed to dilutions of rabbit anti-tetrahymena serum were immobilized in 24 hours. Tetrahymena in this test system were agglutinated at low dilutions and immobilized at higher dilutions. Using an indirect fluorescent antibody test, both organisms showed fluorescence when treated with either rabbit anti-tetrahymena serum or rabbit anti-tomite serum. In heterologous crosses, titers of 1:1024 were obtaibed using the passive hemagglutination test. These results indicate that an antigenic relationship does exist between these two organisms, cross-reacting antigens appear to be localized on the cilia.

Parasites Associated with Ornamental Fish

The diagnosis, treatment, and control of parasites and nonparasitic pests of aquarium fish are covered. Figures are provided that should help the clinician make specific diagnoses.

In vivo and in vitro anaphylactic type reactions in fish

Abstract Anaphylactic type reactions occurred in channel catfish ( Ictalurus punctatus Rafinesque) and goldfish ( Carassius auratus L.) following immunization and challenge with several protein antigens. The reactions were specific for the sensitizing antigen and could be passively transferred to non-sensitized recipients with serum from sensitized fish. In channel catfish the reaction consisted of disorientation, vertical swimming, increased opercular movement and gasping. In the goldfish the reaction consisted of clamping of the fins except the pectorals, loss of equilibrium, and increased defecation. Some deaths occurred with the catfish. The effects of various concentrations of histamine on the rhythmicity and tonus of goldfish and catfish intestinal smooth muscle were also measured in vitro . Isolated intestinal sections were maintained in a Schultz-Dale chamber which was connected to a physiograph. Serum dilutions of histamine, ranging from 100 g to 1000 g were tested. A dose response was observed.

THE IMMUNE RESPONSE OF CHANNEL CATFISH

Channel catfish (Ictalurus punctatus) were immunized with bovine serum albumin (BSA) or vesicular stomatitis virus (VSV). Groups of catfish, housed in cages in a pond, were immunized by intramuscular (IM) injection of single doses of BSA or VSV or 2 doses of BSA or VSV given 1 week apart. Other groups of catfish were immunized with 1 IM injection of BSA or VSV incorporated in Freunds complete adjuvant (FCA). The antibody responses were measured at weekly intervals. Passive hemagglutination was used for detection of anti-BSA antibodies, and serumneutralization was used for detection of anti-VSV antibodies. A significant antibody response occurred in those catfish immunized with either BSA or VSV incorporated in FCA. One injection of BSA or VSV in physiologic saline induced little or no detectable antibody production. Two injections of BSA or VSV in physiologic saline induced a slight transcient antibody response between the third and fourth week post-injection.