Natural history of a solenogaster mollusc from Papua New Guinea,Epimenia australis(Thiele) (Aplacophora: Neomeniomorpha)

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Abstract
Epimenia australis (Thiele) is a large, tropical, shallow-water neomenioid aplacophoran, or solenogaster, of the west Pacific. More than 30 individuals were collected during January and February by diving off Madang, Papua New Guinea, where they occurred in aggregations with their cnidarian prey underneath overturned coral slabs at 15–24 m depth in a steeply sloping coral rock area with swift currents. Animals were kept alive for several weeks in large aquaria with running sea water and fed Scleronephthya. Like other species of Epimeniidae, E. australis is brightly coloured, with iridescent green and blue pactches on a reddish-brown background. Madang specimens were up to 11 cm long and 6 mm in width and were in reproductive condition with brooding embryos in the mantle cavity. Some individuals contained embryos in several stages of development. Epimenia fed on Scleronephthya by clamping onto the soft coral with the hook-shaped radular teeth while sucking in the polyps. They move by ciliary action of the small foot along a mucous strand secreted within the pedal groove; the foot remains within the groove. When not moving, the body can be held rigidly upright. Epimenia were active at night but remained hidden during the day, firmly wrapped around each other and the coral rock on which they were found. The anterior end, with its vestibule containing bundles of papillae and with a dorsal protuberance bordered by sensory cirri, was sensitive to touch, and the animals appeared capable of olfaction, able to find their prey and reacting to each other. The species is redescribed by spicula, radula, and internal morphology. The synonymy of Dinomenia verrucosa Nierstrasz is considered.