Immunoincompatibility Reactions in Corals (Coelenterata)

Abstract

Immunorecognition of allogeneic tissue followed by incompatibility reactions now appears characteristic of the Coelenterata or Cnidaria. Indeed, allogeneic incompatibility has been described in controlled experiments with colonial hydroids (1, 2), anthozoans (3), gorgonians (4) and reef-building corals (5). Although the various antagonistic reactions observed appear quasi-immunological in character, the sequential mechanisms of reactivity remain unknown. Coral allografts and even xenografts may persist in intimate soft-tissue contact for prolonged periods before sensitization leads to tissue destruction (5). However, in certain interspecific combinations, early unidirectional tissue killing may occur, suggestive of non-immunological aggression. Both specific and non-specific defense mechanisms may function depending on the circumstances.