Prosuberites saanichensis, Austin, William C., Ott, Bruce S., Reiswig, Henry M., Romagosa, Paula & G, Neil, 2014

Austin, William C., Ott, Bruce S., Reiswig, Henry M., Romagosa, Paula & G, Neil, 2014, Taxonomic review of Hadromerida (Porifera, Demospongiae) from British Columbia, Canada, and adjacent waters, with the description of nine new species, Zootaxa 3823 (1), pp. 1-84 : 52-53

Prosuberites saanichensis n. sp.

Fig. 19 A–D

Etymology. Named after the type locality, Saanich Inlet, BC, Canada.

Material examined. Holotype: RBCM 982-67-1, VT sta. 14/80, Elbow Point, Saanich Inlet, BC, (48º 32.8'N, 123º 32.4'W), 65 m depth, Sept. 14, 1980, coll. V. Tunnicliffe. Paratype: CMNI 2009-0026, KML 1053, KML sta. 179/83, N. of Maple Bay, Portland Canal, BC, (55º 26.7′N, 130º 01.1′W), 33 m depth, Oct. 25, 1983, coll. W.C. Austin.

Other material: KML 1054, KML sta. 17/76, Princess Royal Reach (Jervis Inlet), BC, (50º 01.1'N, 124º 56.5'W), 33m Mar. 15, 1976, coll. W.C. Austin; KML 1055, VT sta. 8/80, Willis Point, Saanich Inlet, BC, (48º 34.7'N, 123º 29.2'W), 112 m depth, Nov. 21, 1980, coll. V. Tunnicliffe.

Description. Macroscopic features. ( Fig. 19 A). Encrusting, less than 1 mm thick. Shape variable, from roughly circular patches 0.5 to 10 mm diameter to meandering tracts 3 to 10 mm wide that extend up to 50 mm. Oscula 1 mm by 1.5 mm diameter and inconspicuous. Pores not evident. Surface microhispid in some areas, smooth in others. Consistency soft and slightly fleshy. Colour in life yellow brown

Microscopic features. Ectosome about 200 Μm thick, pierced in places by erect vertically disposed spicules, apices outward, extending to 500 Μm beyond the general surface. No evident fence of short tylostyles in the ectosome. Heads of longer spicules reach down to the attachment surface of the sponge. Choanosome about 800 Μm thick, contains both erect spicules and smaller unoriented spicules.

Spicules. Megascleres exclusively tylostyles, typically with suberitid spherical heads; a few curved slightly near head and a few strongylote.

Holotype RBCM 982-67-1

Spicule Type Fig. Length Width

Tylostyles 19B–D 200–(611)–900 7–(12.5)–25 KML 1053

Spicule Type Fig. Length Width

Tylostyles 190–(503)–950 8–(11)–18 Microscleres absent.

Remarks. We placed our material in the genus Prosuberites based on the absence of any distinctly localized size category of tylostyles (van Soest 2002). We have compared our specimens with descriptions of known species world wide.

A form with similar size spicules (175–925 Μm x 7.0–17 Μm) occurs in central California ( Prosuberites sp. of Hartman [1975]); its colour alive, described as gold or hazel, yellow-brown or olive-brown, is similar to our species. However it is only recorded from the intertidal; while our species has been found no shallower than 33 m in BC. It has also been described as having densely packed small upright tylostyles 250 Μm long in the ectosome which would place it in the genus Protosuberites (van Soest 2002).

Thiele (1898) described three species of Prosuberites from Japan. Prosuberites sagamensis has spicules from 400 to 900 Μm long but they are thicker (30 Μm) than those of our species. Both Prosuberites inconspicuus and Prosuberites exiguus have shorter tylostyles. Koltun (1966) made no mention of the genus for far eastern seas of the USSR The tylostyles of Prosuberites longispinus Topsent 1893 from E. Atlantic and Mediterranean are up to 2 mm long, while those of P. psammophilus (Pulitzer-Finali 1978) from the West Indies are up to 1600 Μm long and those of P. laughlini Diaz, Alvarez & van Soest 1987 from Venezuela are up to 1855 Μm long. P. oleteira de Laubenfels 1957, from Hawaii has tylostyles 230 Μm long while P. c o nu l o s u s (Burton 1930) from the Indian Ocean has tylostyles up to 560 Μm long.

Conclusions. The difference in spicule sizes sets our species apart from other species with the exception of the unnamed species from California. That species is described as having an ectosome of densely packed tylostyles 250 Μm in length ( Lee et al. 2007) which indicates that it is a member of the genus Protosuberites as defined by van Soest (2002). The size of spicules and colour difference from described species in the northern hemisphere leads us to conclude the sponge is a new species.

Bathymetric range. 33 to 187 m.

Geographic distribution. To date found at Princess Royal Reach (Jervis Inlet), Portland Canal, Alice Arm and Saanich Inlet, all inner coast, southern to central BC fjords.

Ecology. This is a small encrusting form found on the skeletons of dead hexactinellid sponges or other hard substrates. It frequently occurs on the brachiopod Terebratulina unguicula Carpenter 1864 . This sponge can occur in oxygen concentrations down to less than 0.2 ml/L (based on observations from a submersible).

Figures

FIGURE 19. Prosuberites saanichensis n. sp. A, live specimens on brachiopods, scale bar 5 mm; B, tylostyle, scale bar 50 µm; C, head of tylostyle, scale bar 20 µm; D, pointed end of tylostyle, scale bar 20 µm.