Corallophila woodsidei Huisman

Scientific Description

Habit and structure. Thallus with prostrate axes and assurgent axes to 5 mm tall. Prostrate axes attached by rhizoids arising from periaxial cells at nodes; rhizoids initially unicellular but forming multicellular digitate attachment pads. Erect axes simple or sparingly dichotomously or laterally branched, with straight or slightly curved apices. Prostrate and erect axes 200–220 µm diam. [segment L:B 0.5–1 (shorter near apices)]. Axial cells with (10–) 12–14 (–15) periaxial cells, each cutting off 2 acropetal and 2 basipetal initials. Acropetal initials cutting off four 1- or 2-celled filaments (2 acropetal and 2 basipetal); acropetal filaments each terminating in a tapering cell that stains darkly with aniline blue, these forming a distinct ring around the thallus. Basipetal initials each cutting off 3 filaments, 2 short acropetal filaments and 1 descending basipetal cortical filament; acropetal filaments similar to those arising from the supraperiaxial acropetal cells. Descending cortical filaments straight, confluent, mostly simple or with proximal 1 or 2 cells, each cutting off 1 or 2 cells by oblique divisions; cells mostly aligned in transverse rows, quadrate to transversely elongate in surface view.

Reproduction. Spermatangia arising in extensive fertile regions, covering the thallus. Outer cortical cells cutting off numerous elongate spermatangial mother cells that produce 2 or 3 spermatangia. Other reproductive structures not seen.

Distribution. Known only from Scott Reef, Western Australia. Epilithic in the subtidal.

Habitat. Epilithic in the subtidal.

[After J.M. Huisman in Algae of Australia: Marine Benthic Algae of North-western Australia, 2. Red Algae: 412 (2018)]