Lineolaria spinulosa
The most important difference between Lineolaria spinulosa and L. flexuosa is the presence of the basal hydrothecal spine in the former and its absence from the latter.
The most important difference between Lineolaria spinulosa and L. flexuosa is the presence of the basal hydrothecal spine in the former and its absence from the latter.
Stems minute, scarcely exceeding 0.5 mm in height.
Hydrorhiza broad and flat, reticulated; strongly adherent to the substrate.
Hydrothecae borne directly on the hydrorhiza, usually alternate, normal to the stolon and about 0.5-1 mm apart. Hydrotheca rectangular, perisarc with minute transverse striations, strongly adnate to the substrate for most of length then bending sharply upwards and becoming free in the distal fifth, slightly inflated proximally, narrowing slightly behind margin. Margin oval with two small lateral lobes, immature hydrotheca closed by a delicate membranous flap. Base of the hydrotheca with a strong, erect chitinous spine at junction with hydrorhiza, a small crease in the stolon opposite the spine. Hydranth with about 16 tentacles, capable o f withdrawing deeply into the hydrotheca.
Colonies dioecious, gonothecae large, abundant, usually nestled beside the hydrothecae between stolonal reticulations, male and female similar in shape and size, flattened, irregularly ovate, adnate to the substrate by a peripheral flange about 0.1 mm wide. Aperture distal, circular or sub-circular, facing upwards with a thickened rim and closed by a membranous operculum. Surface of gonotheca with 16-30 small chitinous spines in three or four vaguely defined longitudinal rows, a mass of tissue surrounding the base of each spine.
Gonophore irregularly ovate, the female comprising up to 15 ova arranged in two rows.
Colour: Trophosome transparent and colourless, so that the colony is almost invisible on the substrate. Gonophores cream-coloured.
South Australia
Subtidal, epiphytic on seagrass Posidonia australis.