A comparison of temperature-mediated immunomodulation between two species of flounder.

The kinetics of the temperature-mediated immunomodulation of the humoral antibody response to an erythrocyte antigen was remarkably different in two species of a marine teleost, the winter flounder (Pseudopleuronectes americanus) and the summer flounder (Paralichthys dentatus). These two species were caught in the same area, maintained under the same conditions and injected with the same antigen (horse red blood cells). Experiments were performed at 8, 12 and 17 degrees C during the same time of the year. Summer flounder showed only a delay in the appearance of circulating antibody at lower temperatures while winter flounder showed both a delay and a marked suppression at lower temperatures. Antibody titers remained high for over three months in summer flounder while in winter flounder antibody levels began decreasing after one month.