Dasya kimberleyensis Huisman

Scientific Description

Habit and structure. Thallus dark red to brownish red, mucilaginous, to 24 cm tall, arising from a discoid holdfast, irregularly branched. Axes to 2 mm diam., heavily corticated to the apices, with a dense cover of monosiphonous filaments to 2 mm long. Pseudolaterals borne on every segment, subdichotomously divided 3 or 4 times near base, with (1–) 2–3 (–6) cells between subdichotomies, distally with long simple filaments. Basal cells of monosiphonous filaments thick-walled, 35–60 µm diam., markedly narrower within 3 or 4 cells, then 5–15 µm diam. [L:B 2–5], with occasional intercalary divisions.

Reproduction. Spermatangial stichidia terminal on monosiphonous filaments; fertile region 550–700 µm long, 60–70 µm diam., with whorled spermatangial mother cells bearing numerous ellipsoidal spermatangial. Tetrasporangial stichidia in similar positions, with up to 25 fertile segments, typically only the distal segments with tetrasporangia, each with 5 tetrasporangia and 1 (rarely 2) sporangial cover cells per tetrasporangium. Tetrasporangia spherical, 25–30 µm diam., tetrahedrally divided. Cystocarps lateral on primary axes, sessile or with a short stalk, subspherical.

Distribution. Known from Broome and One Arm Point, Dampier Peninsula.

Habitat. Epilithic in intertidal pools near lowest tide level.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 432–433 (2018)]