Sea Fir

colonial; fixed gonophores

colonies erect and sturdy, 5-12 cm, pinnate, monosiphonic, colour of living colonies amber to honey. Stem slightly flexuose, thicker than branches. Stem only with occasional nodes. Hydrocladia straight, equally and somewhat widely spaced, alternate, with some secondary branching. Hydrothecae of stem and branches similar, biseriate, alternate to subopposite. Hydrotheca flask-shaped, bulbous below, 1/5-1/2 adnate, about 0.9 mm in depth, opening circular, diameter about 0.3 mm, angle of opening with branch axis 45-90°, rim smooth, one circular operculum attached to abcauline side of rim, upper wall of hydrotheca often S-shaped in side view, abcauline wall concave. Gonothecae on hydrocladia, oblong, tapering below, about 1.3 mm long, circular opening on short neck, opening even, inside of neck with ring of perisarc projections. Embryos brooded in acrocysts.

Widely recorded on both sides of the North Atlantic Ocean from the arctic region to Madeira, all Arctic Oceans, in the North Pacific Ocean south to California and Japan. Also known from Madagascar (Cornelius 1995b). Known also from eastern and western Greenland. At Iceland it occurs all around the island, depth range of 10-630 m.