Article: Structure and incremental growth in the ahermatypic coral Desmophyllum cristagalli from the North Atlantic
Desmophyllum cristagalli has some characteristics in common with other ahermatypic corals living in deep water (2000 m for our specimens). This weakly colonial species is characterized by a theca greatly thickened by deposition of stereome, also forming massive deposits within the corallite and sometimes completely filling it. Septal trabeculae are uniformly small in diameter in this species, and tend to blend into a fine-grained septal 'dark line' when seen in transverse thin section. These characteristics are seen elsewhere in the family Caryophylliidae and also are noted in some other deep-water-dwelling ahermatypic corals. Incremental, perhaps periodic, growth of exoskeleton is noted in these specimens of D. cristagalli, although they originated in a deep, apparently stable environment.