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Dendrophylliids are known from the Early Cretaceous (about 120 million years ago) to the Recent, and are widespread in today's oceans from the North Sea to the Subantarctic, ranging in depths from 0 to 2165 meters. Because most dendrophylliid genera and species do not rely on unicellular, photosyntethic zooxanthellae symbionts, they can live in deep-water environments or cryptic (caves or under ledges) shallow-water habitats that do not receive light. Only a few genera (Turbinaria and Duncanopsammia, and some species of Heteropsammia) contain zooxanthellae in their polyps and consequently manufacture large skeletons that contribute to shallow water reef structure. The remaining genera and species (approximately 149 of the 166 Recent species, 90%) are azooxanthellate. There are an additional 198 exclusively fossil species (Cairns, 2001). The azooxanthellate dendrophylliids range in size from small solitary, interstitial coralla only 5 mm in maximum diameter (e.g., Notophyllia) to large colonies up to a meter in diameter (e.g., Enallopsammia) that, together with similar colonies, contribute to the framework of deep-water coral banks found at depths of 600-800 m in the Straits of Florida (Cairns and Stanley, 1982).
Left (top): Dendrophyllia oldroydae: Holotypic colony, collected from off California (depth 366 m). This species is an example of a colonial, azooxanthellate dendrophylliid. Colony 83 mm in height (from Cairns, 1994). Right (bottom): Notophyllia recta: Calicular view (SEM) of a skeleton collected off Victoria, Australia (depth 110 m), exemplifying a solitary, unattached dendrophylliid. Greater calicular diameter 5 mm. Photograph from Cairns and Parker, 1992. Copyright © 1992 South Australian Museum.
As stated above, dendrophylliids occur as solitary polyps or as colonies of interconnected polyps. Most colonial dendrophylliids are firmly attached to a substrate, probably in order to stabilize their larger mass, but solitary coralla may be attached or free, some on or in a sandy substrate. Two genera (Heteropsammia and Wadeopsammia) have an obligatory symbiosis with a sipunculid worm (Yonge, 1975), which burrows into the base of the solitary corallum and moves the coral from place to place. Some genera (i.e., Endopachys, Eguchipsammia, Balanophyllia) are known to asexually bud smaller coralla from their edges, the parent corallum continuing to increase in size, and one genus (Notophyllia) asexually propagates by transverse division. Six genera are hosts for the galls of ascothoracidan Crustacea (Grygier and Zibrowius, 1985), and two genera are hosts for burrows of acrothoracican cirripeds (Grygier and Newman, 1985; Cairns and Zibrowius, 1997).
Although dendrophylliids are common in the marine environment, they are inconspicuous and therefore are not well known and have not received many common names. However, many of the scientific names of the genera end in the suffix "-psammia", from the Greek psammos (meaning sand), which is an allusion to the fact that the skeletal porosity of all dendrophylliids confers a rough, sandy texture to the touch, like that of fine sandpaper.