Fascaplysinopsis ronquinni Ekins, Erpenbeck & Hooper sp. nov.

Figures 3, 9

urn:lsid:zoobank.org:act: EEE97708-3A2B-4C9A-A710-58A53A43B15B

Material examined.

Holotype QM G339083, East point, Nukuhifa Island, Wallis, 13.287833°S, 176.11885°W, 30 m, Exterio Face of the Barrier Reef, P638, WLF14, Coll M. Ekins, E. Folcher, S. Petek. IRD—Institute De Recherche Pour Le Developpement, 25/VII/2018.

Paratype: QM G333292, Mehetia, Society Islands, French Polynesia, 17.885167°S, 148.07423 ° W, 20 m, SCUBA, P229, Coll. E. Folcher, IRD—Institute De Recherche Pour Le Developpement, 26/IV/2011.

Etymology. Named after the Professor Ronald J. Quinn, AM, Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia in recognition of his lifetime work on marine natural products, including the ones from sponges collected by the Queensland Museum.

Distribution. This species is currently known from Wallis, Territory of the Wallis and Futuna Islands, and Mehetia, French Polynesia, in the South Pacific (Fig. 3).

Description:

Growth form: The holotype is a massive partially burrowing sponge 40 mm long and 25 mm wide and 25 mm in height, with fistules emerging from the sand. These small turrets are 2–2.5 mm in diameter and are 5 mm in height (Fig. 9 A–B). The paratype is similar in morphology and size at 50 x 50 x 40 mm, with 2.5 mm in diameter turrets, but up to 15 mm in height.

Colour: The sponge is dark brown to black underwater and on deck. The interior colour is also dark brown/ black. In 70% ethanol, the exterior is a light to dark grey. The fibres are a red/brown hyaline colour.

Oscules: The oscules are located apically on the end of the turret like fistules. The oscula openings are approximately 1–2 mm in diameter.

Texture: The sponge is compressible, firm and fairly tough.

Surface: The exterior has a microconulose surface, with the conules 0.2–1 mm in height. The fibres are exposed 1 mm above the surface and separated by only 1 mm. The surface is covered with and other animals and plants, some of which appear to be growing through the sponge (i.e. octocorals and hydroids).

Ectosomal skeleton: The ectosomal is composed of a translucent grey membrane (Fig. 9 C).

Choanosomal skeleton: The choanosome is composed of thick collagenous material, the dark pigmentation from the ectosome bleeds into the upper choanosome. The skeleton forms a polygonal grid of 0.5 to 1 mm between primary fibres and only 100–500 μm between secondary fibres. The primary fibres are of large (150–250 μm in diameter) laminated and cored (Fig. 9 D). The secondary fibres are about 50 μm in diameter, whilst the rare tertiary fibres are 15–20 μm in diameter. The secondary and tertiary fibres are laminated and clear of debris or pithing (Fig. 9 E–F).

Ecology. This uncommon species occurs as a semi burrowing sponge in sandy substrates on the lower level of outer barrier reefs at 20– 30 m. It has encrusting epibionts on its surface including: algae, ascidians and sponges.

DNA Barcodes. 28S: QM G339083 (OX458935)

Remarks. This new species from the South Pacific is the only species in this genus that is burrowing. It is also unique in that all of the primary, secondary, and tertiary fibres are much darker than in other species and are pigmented. This new species also lacks pithing in the secondary and tertiary fibres.