VARIATIONS IN THE CHEMICAL COMPOSITION OF THE SKELETONS OF NON-ZOOXANTHELLATE SCLERACTINIAN (ANTHOZOA: SCLERACTINIA) CORALS

Abstract

Nonreef-building scleractinian corals (which lack zooxanthellae, endosymbiotic algae) are known to have a carbonate skeleton, similarly to colonial reefbuilding corals living at depths of up to 50 m. However, in contrast to reef-building corals, these species are represented mostly by solitary forms inhabiting broad ranges of depths (from a few dozen to >6000 m) and temperatures (from 20 to –1.1°ë). The average diameter of the cups of individual corals ranges from 1 to 4 cm. Much less non-zooxanthellate genera are colonial forms that produce cold-water coral banks at various latitudes and depths in the ocean. They occur mostly at depths from 60 to 900 m at high latitudes. In the tropics and subtropics, colder water species occur at depths of 1000–2600 m, mostly at the foots of seamounts.