Membrane damage by coelomic fluid from Holothuria polii (Echinodermata).

Rabbit erythrocyte membranes lyzed by Holothuria polii coelomic fluid, observed under the electron microscope, present lesions consisting of irregular holes which are heterogeneous in size (ranging from 50 A to 250 A) and ultrastructurally different from the ring-like structure produced by human complement. The protein pattern associated with the lyzed membrane was also examined.