title: Influence of temperature on the immune response of juvenile summer flounder, Paralichthys dentatus, and its role in the elimination of Trypanoplasma bullocki infections.
abstract: Two groups of juvenile summer flounder maintained at 5 degrees C were experimentally infected with the hemoflagellate Trypanoplasma bullocki. Another group maintained at 5 degrees C was not infected. The water temperature of one infected group was raised stepwise to 12 degrees C, 18 degrees C, and 24 degrees C for 2 to 3 weeks at each level. The other infected group was maintained at 5 degrees C for 12 weeks, the duration of the experiment. In addition, juvenile flounder were collected over a temperature range of 6 degrees C to 22 degrees C from February to June, 1982, to monitor natural infections. Live T. bullocki were incubated in plasma from fish at each temperature to monitor the host's humoral response. Trypanoplasmacidal lysis occurred in experimental infections maintained at 24 degrees C and in natural infections over a range experimental infections at 24 degrees C and in natural infections at 22 degrees C. Differences in temperature where lytic activity occurred was mainly attributable to the short time exposure of experimental infections to increasing temperatures in contrast to that occurring in nature. Trypanoplasmacidal lysis with increasing water temperatures in flounder indicates that the fish's humoral immunity is responsible for the annual spring decline in prevalence and eventual elimination of T. bullocki infections.
mesh_terms: D000818:Animals; D000906:Antibodies; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes / Q000276:immunology* / Q000469:parasitology; D013696:Temperature
chemical_list: D000906:Antibodies