Cortisol responses of pallid sturgeon and yellow perch following challenge with lipopolysaccharide

Plasma cortisol responses of pallid sturgeon Scaphirhynchus albus and yellow perch Perca flavescens following injection with equal doses of lipopolysaccharide were compared. Concentrations of cortisol in plasma from pallid sturgeon did not change following injection (6·0–11·0 v. 6·4 ng l−1 pre‐stress) while in yellow perch plasma they were shown to increase up to 6 h (117·0 v. 9·8 ng l−1 pre‐stress) after the injection. These results are consistent with other reports for pallid sturgeon that illustrate a reduced cortisol response following other applied stressors relative to teleosts and suggest differences in the expression and regulation of their inflammatory responses.