Oceanapia flava, Ott & Mcdaniel & Humphrey, 2024

Ott, B., Mcdaniel, N. & Humphrey, E., 2024, Fourteen new species of demosponges (Porifera) from three coastal fjords in southern British Columbia, Canada, Zootaxa 5463 (2), pp. 151-200 : 185-187

Oceanapia flava n. sp.

urn:lsid:zoobank.org:act:4F1072FF-FD17-4665-8857-C01FC7826E9F

Figure 14

Diagnosis. Encrusting, micro-hispid, thin-walled fistulae terminating in oscula, bright yellow. No microscleres.

Etymology The species name refers to its yellow colour, unlike its BC congenus which is white.

Material Examined Holotype RBCM 024-0017 - 001 , Stn NM 412 , Sakinaw Rock, Sechelt Inlet, BC, 49° 33.988’ N / 123° 48.174’ W, coll. N. McDaniel, 20 Jan 2020, 10 m depth, 1 specimen . Paratypes RBCM 018- 00141 - 001 , Stn NM 331 , Sakinaw Rock, Sechelt Inlet, BC, 49° 34.005’ N / 123° 48.194’ W, coll. N. McDaniel, 25 Feb 2016, 5 m depth, 1 specimen ; RBCM 023-00001 - 002 , Stn NM 354 , Sakinaw Rock, Sechelt Inlet, BC, 49° 33.988’ N / 123° 48.174’ W, coll. N. McDaniel, 28 Nov 2016, 10 m depth, 1 specimen . Other Material Stn DG 171209, Gambier Isl. , Halkett Bay, Annapolis Reef, BC, 49° 27.325’ N / 123° 22.294’ W, coll. Donna Gibbs, 9 Dec 2017, 22 m depth, 1 non-voucher specimen .

Description

External ( Figure 14A ) Holotype RBCM 024-0017-001 Encrusting, forms extensive, continuous encrustations up to 50 cm or more long, often fouling mooring lines. Surface with conical tubular fistulae either singular with an osculum or multiple (2 to 4) and blind. Papillae densely packed on the surface of the sponge. Surface of papillae smooth. Oscula 1–3 mm diameter at the top of fistulae; many fringed on the top. Fistulae straight sided except contracting near the tip if single; otherwise very irregularly shaped. Single tubes 15 to 20 mm high by 4 mm at base. Larger fistulae form a conical fringe on the top. Main sponge body surface very irregular with small processes (3 to 8 mm high; may be proto fistulae); cavernous. Ostia abundant over the entire upper surface, average 1 mm diameter. Surface microhispid with spicules protruding to 250 µm. Colour yellow. Texture: soft, easily torn. Fistular fringes are composed of sponge tissue and oxeas packed closely together and aligned with the long axis of the fringe. Fringes average 0.9 wide by 1.2 mm high.

Skeleton ( Figure 14B ) Fistula ectosome layer 150 µm thick consisting of tightly packed tangential oxeas randomly displaced on the inner surface and more open on the outer surface. Below the ectosome is a discontinuous layer of cavities of highly variable dimensions from 40 by 250 µm up to 400 by 700 µm diameter. Fistula choanosome cavernous. The choanosome below the ectosome or subectosomal cavities is formed of a network around the cavities and composed of spicule tracts 10 to 20 to a side, forming 50 by 100 µm diameter elliptical spaces within the tracts. Ellipses may be randomly cross connected by single or bundles of 2 or 3 oxeas. Main sponge body choanosome cavernous. This choanosome has the same structure as the fistulae except that the oxeas in the surface ends of the spicule tracts regularly penetrate the ectosome and up to 250 µm making the surface microhispid.

Spicules ( Figure 14C ) Oxeas: gently curved, fairly uniform shaft, one or both apices acerate tapering from centre; occasionally slightly telescopic, dimension range 210–441 x 6.5–13.0 µm. As well, oxeas may have hastate sharp apices. Some juveniles present. Table 14 lists spicule dimensions of specimens examined.

Distribution Howe Sound and Sechelt Inlet, BC; 5–22 m depth.

Ecology The species thickly colonizes mooring lines or bedrock.

Remarks. Three published Oceanapia species are located in the North Pacific: one for the Gulf of California and two from Japan. Oceanapia pacifica ( Dickinson, 1945) , was dredged from 150 m depth from the Gulf of California. The sponge habitus consists of 0.5–1 cm diameter chimnies arising from a base. The surface is tough, leathery with abundant ostia 0.5 mm diameter and oscula 2–3 mm diameter on ends of chimneys; colour was white. Dickinson describes the ectosome as tough without elaboration. The choanosome is reticulate. The habitus, colour and choanosome are similar to O. polytuba n. sp. but Dickinson’s sponge has oxeas to 1300 µm or much larger than O. polytuba n. sp. Two shallow water (15–30 m) Oceanapia species were described by Hoshino (1981) for Japan: O. ooita ( Hoshino, 1981) and O. toxonisimilis ( Hoshino, 1981) . Both are multi-tubular arising from bases. Both have reticulate choanosomes; the ectosome of O. ooita is unorganized whereas that of O. toxonisimilus is reticulate. However, O. ooita has common microscleres of sigmas and toxas and O. toxonisimilus , as the species name implies, has centrally curved thin oxeas ressembling toxas.

Oceanapia flava n. sp. habit of growing on buoy lines is not shared by any of the three previously described North Pacific Oceanapia species, nor with O. polytuba n. sp. The ectosome structure of O. flava n. sp. as well as habitus differs from O. polytuba n. sp. Spicule dimensions of the two new BC species are:

Oceanapia polytuba n. sp. 123–263 x 2.5–15.0 µm

Oceanapia flava n. sp. 210–441 x 6.5–13.0 µm

Figures

FIGURE 14. Oceanapia flava n. sp. Holotype RBCM RBCM 024-0017-001 (A) In-situ on algal covered anchor rope. (B) Skeleton cross section, sponge surface on left, algal covered rope on right; protruding tube is an alga. (C) Oxea.