EFFECT OF SIZE AND TEMPERATURE ON THE QUANTITY OF IMMUNOGLOBULIN IN CHANNEL CATFISH, ICTALURUS-PUNCTATUS

Concentrations of serum immunoglobulin (Ig) were determined for 30 channel catfish from pond water at 10°C. These values were compared to measurements of 15 channel catfish from pond water at 30°C. Channel catfish from 10°C pond water had no significant (P>0.05) different Ig concentrations (mean, 398 mg/dl) than catfish from 30°C pond water (mean, 367 mg/dl). Serum Ig concentrations appear not to be different in cold (10°C) vs warm (30°C) pond water for 37.5-45 cm catfish. Channel catfish, 7.5-15 cm (n=24) had significantly (P<0.05) lower Ig levels (mean, 104 mg/dl) than catfish either 7.5-25.5 cm (n=57, mean, 232 mg/dl) or 37.5-45 cm (n=45, mean, 388 mg/dl). Also, catfish 17.5-25.5 cm had a significantly (P<0.05) less Ig than catfish 37.5-45 cm. The concentrations of serum Ig increase with size (P=0.0001) of catfish. The mean Ig concentration for 7.5-45 cm catfish (n=126) was 263 mg/dl. The Ig concentration range was 44 to 650 mg/dl of serum. © 1990.