The effect of infection by gram-negative bacteria, and their endotoxins, on the blood-clotting mechanism of the crustacean Sacculina carcini, a parasite of the crab Carcinus maenas

Abstract

The cell-free clear plasma of healthy specimens of the parasitic crustacean, Sacculina carcini, coagulates into a nonretractable gel on contact with glass. Infection of the body cavity of Sacculina with gram-negative bacteria, or the injection of endotoxin from gram-negative bacteria, causes internal coagulation so that fluid subsequently obtained is incoagulable. The apparent exhaustion of coagulation is accompanied by progressive infection and death of the parasite. It is suggested that this endotoxin-stimulated coagulation functions as a protective mechanism against trauma and infection of the exposed parasite.