Mycale (Grapelia) australis (Gray, 1867)

Figs 56 a–f

Hymeniacidon spec. Bowerbank 1864: fig. 135.

Grapelia australis Gray, 1867: 534 .

Esperia parasitica Carter, 1885: 108, pl. IV fig. 1.

Pseudoesperia enigmatica Carter, 1886: 455 .

Esperella enigmatica; Dendy 1896: 14.

Mycale parasitica var. arenosa Hentschel, 1911: 311, fig. 13; Guiler 1950: 8.

Mycale (Mycale) parasitica var. arenosa; Shaw 1927: 423.

Mycale parasitica; Carpay 1986: 31, 71 fig. MC1.

Mycale (Grapelia) australis; Hajdu 1995: 74, figs 6.1–12; Van Soest & Hajdu 2002: 680, fig. 7.

Material examined. ZMA Por. 10712, Australia, Tasmania, Stockyard Point, 43.2°S 144.3°E, depth 6 m , SCUBA, coll. M. Carpay, 10 December 1984 (beige-yellow) .

Summary description (Partially after Hajdu 1995). Massive, rather globular, sponge (Fig. 56a), with dimensions 11 x 15 x 5 cm (rather similar to the neotype specimen BMNH 1886.12.1.5.467 depicted in Hajdu 1995 figs 2–3). Beige to mustard-yellow alive, beige in preservation. Surface optically smooth, with scattered oscules of 5–8 mm in diameter and one larger vent-like depression of 3 cm in diameter and 1 cm deep. Surface provided with clear, partially detachable, crust, where damaged showing underlying skeletal reticulation. Consistency compressible. Skeleton (Fig. 56b) plumoreticulate, with strongly developed spicule tracts, up to 300 µm in diameter in the deeper parts, down to 60 µm diameter in subsurface tracts. Thicker tracts are irregularly interconnected by thinner tracts at varied angles. Subectosomal skeleton partially consisting of unispicular brushes upon which rests the confused tangential ectosomal skeleton strengthened by foreign material. Rosettes (Fig. 56b) of 15–20 anisochelae I (105–110 µm in diameter) and II (average 45 µm in diameter) are numerous and contribute to the surface skeleton. Spicules (Figs 56 c–f) robust mycalostyles (Figs 48c,c 1) with barely swollen heads, usually curved, sometimes bent in opposing directions, 345– 377.0 –405 x 8– 12.8 – 15 µm, moderately strongly curved anisochelae I (Fig. 56d), with unguiferous upper alae, and squarish lower alae, 43– 51.6 – 60 µm, anisochelae II (Figs 56e,e 1) with three-pronged serrated flattened upper alae (Fig, 56e1) and lightly serrated lower alae (Fig. 56e 1), 18– 20.2 – 22 µm, and spurred anisochelae III (Fig. 56f), with lateral upper and lower alae meeting along the shaft, 15– 16.9 – 19 µm. No sigmas (erroneously reported by Carpay 1986, mistaking these for the anisochelae II).

Distribution. South and West Australia, including Tasmania.

Remarks. The difference in size between anisochelae II and III is supposedly the opposite of what is found in M. (G.) ancorina . However, the size of anisochelae III is overlapping with that of anisochelae II, and it is minimal between anisochelae of M. (G.) ancorina (18–22 µm) and M. (G.) australis (16–19 µm), so the value of the distinction between the two species appears to be dubious for this feature. The main difference between the two sympatric Australian species remains the habitus (arborescent in M. (G.) ancorina and massive globular in M. (G.) australis).

West Australian M. (G.) carteri (Dendy & Frederick, 1924) is a further species similar to the above in general aspects, including habitus and shapes of anisochelae, but differs sharply from the present species and also from M. (G.) ancorina in the possession of sigmas. Likewise, the Madagascan M. (G.) vaceleti Hajdu, 1995 is close to the present species but the holotype contains rare sigmas (not the paratype apparently), and sizes of anisochelae I and III differ substantially.