Anthothela

Diagnosis. With slender, rounded, tortuous, commonly upright, abundant anastomosing branches producing tangled colonies. Branches always solid; no main stems developed, branches grading upwards from broadened membranous base. Polyps present on base as well as on branches, widely scattered on all sides, sometimes clustered into large masses. Polyps elongated in expansion arising from distinctly projecting, short yet elevated cylindrical calyces. Polyps partially retractile, seldom entirely retractile; large anthocodiae commonly preserved exsert, arising from either extended, rather thin, slightly sharp, spiculose, but spongy, basal membrane (encrusting) or from slender irregular stems (branched). Axis spiculose, well differentiated, not firm. Long, strongly warted, often irregular spindles and short, girdled rods in coenenchyme. Sclerites of axis more irregular; bear fewer, larger warts, knobs or lobes. Spongy base filled with thin spindles and rods, permeating tissue. Bright rosy-red or brownish in life, but other color forms likely.

Diagnosis: Monomorphic scleraxonians which form both membranous and branched colonies. Branched colonies are tangled with no central or main stem; anastomoses common; cortex separated from medulla by a ring of intact coelenteric canals (boundary canals); coelenteric canals almost always absent from central medulla (occasionally present as only a thinning in the density of sclerites); calyces distinct, cylindrical to conical, spread irregularly throughout colonies with some free space between but tending to crowd together at branch tips; polyps often exsert but may be partly or fully invaginated into calyces; medulla sclerites are straight, simple sticks and spindles with light to moderate tuberculation; all other sclerites are sticks and spindles, clubs and hockeystick spindles, many clubs being bent with thorny tips; sticks and spindles are arranged as collaret and points on polyp head and longitudinally along the aboral side of the tentacle rachis; pinnules are crowded with longitudinally arranged, narrow spatulate clubs; the pharynx has small tuberculate rods. Membranous colonies are as above but lack a medulla.

Remarks: Specimens of Anthothela have historically been understood to be of relatively common occurrence amongst deep-water samples from the Northern Atlantic. In reality, the understanding of Anthothela had been so modified and expanded as to ultimately incorporate specimens which were actually from other genera. The removal of these specimens means the diagnosis of Anthothela has now been refined and tightened. The worldwide distribution of the genus remains with confirmed records from the North and South Atlantic Ocean, southern Indian Ocean, North and South Pacific Ocean and on the northern boundary of the Southern Ocean. All occurrences are restricted to cold waters with most specimens collected deeper than 100 m down to over 1800 m in depth.

Type species: Briareum grandiflorum Sars, 1856, by designation