Size

Colony height: reaching 3.5cm (1.4") Colony width: 1.25cm (0.5")

Recognition Characters

Colonies of this hydroid form beautiful feather shaped plumes arising from individual hydrorhiza. There may be several plumes clustered together when found. The central trunk of the hydrocaulus is monosiphonic, straight, and divided into internodes with hydrothecea alternately opposed (approximately 3 hydrothecae per node). Outer branches of hydrocaulus have hydrotheca directly opposed (2 per node). Hydrothecae on outer branches face outward and are bent at nearly 90° angles.

Color

Branches are white with hydrocaulus sometimes darker tan or brown.

Habitat & Depth

Attach to reefs, wrecks, and hard bottoms. Also found attached to floating sargassum. Surface waters to 30m deep.

Distribution at GRNMS

Occasional. Small colonies may be encountered encrusting rocks.

Geographic Range

North Carolina south to Florida, Bermuda

Behavior & Notes

This species in known to produce the chemical, tridentatol A, which is highly effective at blocking UV rays that cause skin cancer and wrinkling.

Synonyms

References