Chondria thielei Huisman

Scientific Description

Habit and structure. Thallus upright, deep red, to 19 cm tall, with several percurrent primary axes arising from a discoid holdfast. Erect axes sparingly branched laterally, often secundly, and causing the primary axis to curve, with rounded apices and pointed tips. Trichoblasts borne near branch apices and in association with emergent lateral branches, dichotomously divided. All axes terete; primary axes to 2 mm diam., tapering evenly to c. 1 mm diam. near apices. Lateral branches markedly constricted at base, similar to primary axes or slightly narrower, 1.0–1.5 mm diam. Cortical cells in surface view 12–17 µm diam., mostly elongate, 35–120 µm long [L:B 1.5–10]. Cell wall thickenings absent.

Reproduction. Spermatangial plates borne on trichoblasts associated with branch primordia along axes, discoid to oval, 680–870 µm wide, with a marginal row of sterile cells. Tetrasporangia in stichidial branches associated with branch primordia. Stichidia basally constricted, to 1.3–2.0 mm long, 400–500 µm diam., with tetrasporangia in a spiral pattern, spherical, tetrahedrally divided, to 120 µm diam. Other reproductive structures not observed.

Distribution. Known from Barrow Island and the Dampier Archipelago, Western Australia.

Habitat. Epilithic in the subtidal to 11 m depth.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 496–498 (2018)]