Effect of size and temperature on the quantity of immunoglobulin in channel catfish, Ictalurus punctatus

Abstract

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.