Ancorina stalagmoides Dendy 1924

Ancorina stalagmoides (Dendy 1924)

( Fig. 1 B, 4D–H, 8)

Ancorina stalagmoides Dendy, 1924: 297, pl. III, Fig. 4, pl. VII, Fig. 12–15. Ancorina stalagmoides, Bergquist (1968: 40).

Material examined. NIWA 49896: 3 nautical miles east of North Cape, 34.412° S, 173.150° E, 133 m, 19 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6697-O) and at the USNM (USNM 1182985); NIWA 49897: TAN9915-AA, Stn 3B, Ngunguru Bay, Tutukaka, 35.697° S, 174.648° E, 80 m, 13 Dec 1999; NIWA 62162: TAN0413/138, Mahia Knoll, Bay of Plenty, 37.316° S, 177.075° E, 466–495 m, 14 Nov 2004; NIWA 44455: Stn E848, north of the Three Kings Islands, 33.983° S, 171.667° E, 17 Mar 1968, 250 m; NIWA 75683: TAN1108/275, Ranfurly Bank, northeast of East Cape, 37.316° S, 178.943° W, 145–155 m, 0 3 Jun 2011.

Other material. Ancorina stalagmoides: NHMUK 1923.10.1.24 (syntype), dry subsample from R. N. XXXIII. 1; NHMUK 1923.10.1.23 (syntype), dry subsample from R. N. XXXIII. 6; NHMUK 1923.10.1.220, NHMUK 1923.10.1.402, NHMUK 1923.10.1.115, microscope slides from R. N. XXXIII. 1, 6: unidentified Terra Nova Stn, off Three Kings Islands, British Antarctic (Terra Nova) Expedition, 1910, 16 Jul –24 Sep 1911.

Type locality. Three Kings Islands.

Distribution. Three Kings Islands, North Cape, Tutukaka, Bay of Plenty.

Description. Massive, sculpted sponge, 190 x 170 mm with an apical depression and deeply corrugated/ sculpted growths projecting outwards and downwards (Fig. 1 B). Small oscules are scattered in the apical and lateral depressions, about 2–3 mm diameter. Texture compressible, velvety to the touch and hispid in places, interior is very harsh and siliceous. Entire surface is encrusted with Desmacella dendyi de Laubenfels (Poecilosclerida: Desmacellidae), up to 3 mm thick. Colour in life is orange owing to the encrusting D. dendyi, interior is tan, which changes rapidly to pink upon exposure to air. Colour in ethanol is dark tan, interior is medium brown.

Skeleton. Ectosome about 1200 µm thick, cavernous with aquiferous canals, with a thick band of dark granular ‘fibrous’ collagen, along the ectosome/choanosome boundary. Sanidasterhabds are moderately dense at the surface of the sponge and scattered below. Dense bundles of large oxeas and triaenes radiate out from the centre of the sponge towards the surface. Triaenes are abundant at the surface of the sponge, arranged in tight brushes, with their cladomes uppermost. The pitchfork-like cladomes of the protriaenes and dichotriaenes extend beyond the ectosome and encrustation of D. dendyi, rendering the surface particularly harsh and scratchy. The choanosome is more heavily pigmented than the ectosome and densely packed with oxyasters. Oxyasters and smaller microscleres are scattered throughout the ectosome.

Spicules. Megascleres (Fig. 4 D–E) are oxeas, large, stout, fusiform, very slightly curved with sharply pointed ends, 3576 (2941–4114) x 86 (58–109) µm; protriaenes (Fig. 4 D), large, stout spicules with a pitch-fork shape, rhadome length 3043 (2421–3924) µm, clad length 315 (213–430) µm, cladome width 290 (241–361) µm; prodichotriaenes (Fig. 4 E), large, stout spicules with a long, gradually tapering rhabdome, 3015 (2486–3592) µm, and forward arching clads. Cladi are short and stout, protoclads are 141 (87–203) µm long and protrude at an approximately 45° angle from the shaft, deutroclads are 116 (67–139) µm long and protrude at 60–70° from the shaft, cladome is 433 (301–570) µm wide.

Microscleres (Fig. 4 F–H) are oxyasters I (Fig. 4 F) with around 7–10 slender rays that are sharply pointed at the ends, and lightly spined, 15 (12–18) µm diameter; oxyasters II, smaller than oxyaster I and with more rays, 6 (4–9) µm diameter (Fig. 4 G); sanidasterhabds (Fig. 4 H), with acanthose irregular spines, frequently with a central restriction, producing a dumbbell-like shape, 5 (4–6) µm long.

Substrate, depth range, and ecology. Coral rubble and rocky substrate; found between 80– 495 m.

Remarks. Ancorina stalagmoides is distinctive in morphology, forming a sculpted mass, and in the form of the prodichotriaenes and dichotriaenes which resemble pitch-forks. The thick ectosome with fibrous granular collagen at the lower boundary is characteristic of Ancorina and similar to that of both A. diplococcus and A. bellae sp. nov. The sanidasterhabds are similar in form to those of A. diplococcus in that they are dumbbell-shaped, but the acanthose spines are less densely packed. Under light microscopy these are easily mistaken for the acanthomicrorhabds of Ecionemia, but careful observation reveals the inherent irregularity and spininess of these microscleres. The choanosomal oxyasters are common, but are much smaller and less abundant than those in A. diplococcus and A. bellae sp. nov.