Holotype: TM K1717, CSIRO Cruise SSO1/97, 44.27°S 147.33°E to 44.24°S 147.36°E, depth 987 m, 83.8 km SSE of South East Cape, Tasmania. Female colony 45 mm high, detached from substrate; microslides MV F83434 & 83435, RMNH-Coel. 29003, slide 4453 parts of holotype colony.
Immature gonothecae are kidney-shaped, exposing the twin upwardly-facing, gonophoral hydrothecae seated on the pedicular tumescences; by maturity, the hydrothecae are almost enclosed by coiling of the distal end of the gonotheca.Thinning and rupture of the internal distal wall of this enclosure permits escape of the ova.
Named for the late Patricia M. Ralph.
Hydrorhizal filaments reptant on coral; colony aborescently branched in up to three orders. Branching occurs from below a hydrotheca, stem and branches heavily fascicled, polysiphonic tubes almost linear to undulating, sometimes knotted around origin of branch, tubes running along branches, ultimate branches monosiphonic. Perisarc of stem and proximal branches thick, thinning out on monosiphonic parts.
Monosiphonic branches (Hydrocladia) flexuous, often bifurcate, internodes variable in length, usually long and slender, widening distally to a node just above primary hydrophore. Monosiphonic branches arising from polysiphonic tubes on an apophysis of stem comprising one to three subspherical segments with strong transverse nodes. Hydrocladial internodes long, cylindrical, smooth, widening distally, nodes slightly oblique, tilted away from hydrotheca, marked by a deep constriction and tumescence in perisarc, sometimes an additional short subspherical internode similar to apophysis above node.
Hydrophores alternate, distal on internode, almost entirely adnate to internode, adcauline wall marked by a seam in perisarc, a semicircular thinning in perisarc below some hydrothecae; abcauline wall contiguous with wall of internode.
Hydrotheca free, closely adpressed but not adnate to internode, very shallow, tilted at slightly away from internode, hydrothecal margin very weakly everted, diaphragm distinct, a ring of desmocytes above.
Gonothecae large, borne distally on monosiphonic branches, usually facing distally on branch, seated on a long expanding pedicel inserted into a short tumid apophysis opposite or below a hydrophore; pedicel merging into base of gonotheca. Mature gonotheca coiled into a flattened disk; perisarc thin, a tumescence (visible only in transverse view) on each side of gonotheca at junction with pedicel; recurvature of distal region onto lower body producing a cavity partially filled by a pair of upwardly-facing hydrothecae with reduced hydranths, seated on the pedicular tumescence. A subcircular thinning of perisarc is visible in the distal wall inside the cavity. Gonophore a chain of up to ten large ova following curve of gonothecal wall.
Colour: Stem and fascicled branches honey brown; monosiphonic parts pale brown.
Distribution Pacific (Japan, Chatham Islands and Tasmania).
Subtidal to deep sea (>400 m), epizoic on corals and other invertebrates.