Key to Families of Shallow Water (0-200m) Octocorals of the South Atlantic Bight

Subclass Octocorallia (=Alcyonaria) - Couplet 1

1a. – Colonies attached to substrate with a basal disc or holdfast. Colony generally moderately branching to highly arborescent (although a few species may have a single unattached stalk). No leaf-like structures. No oozooid present. Cortical sclerites present in all species; medullar or axial sclerites present in some species
Order Alcyonacea............................…...…2

top left: Bellonella rubistella, showing base attached to substrate; top right: branching pattern of Muricea pendula; bottom: holdfast of Muricea pendula

1b. – Colonies with a basal muscular peduncle for anchoring in soft substrate. Growth form foliose, bilateral, whip-like or clavate, but not branching, sometimes with leaf-like structures on stem. oozooid present, with autozooids and siphonozooids on rachis. Sclerites usually present in form of three-flanged rods, plates or needles, never spindles, but absent in axis
Order Pennatulacea…....................................…9

left: Sclerobelemnon theseus, showing peduncle; middle: Renilla reniformis, showing peduncle; right: Virgularia presbytes, showing leaf structures