DIETARY PROTEIN REQUIREMENTS OF THE RED CRAWFISH, Procambarus clarkii (GIRARD) (DECAPODA, CAMBARIDAE), GROWN IN A CLOSED SYSTEM

Isolated juvenile crawfish, Procambarus clarkii (Girard), were fed water‐stable, extruded diets that varied in gross protein levels (19.6–46.0%) and gross animal protein substrate levels (15.0–44.0%). Results indicated that gross protein requirements were in the 20–30% range and that gross animal protein substrate requirements were in the 15–20% range. All diets appeared to be deficient in dietary carotenoids as evidenced by the development of an abnormal blue body color by all crawfish.