Ecionemia alata Dendy 1924

Ecionemia alata (Dendy 1924)

(Fig. 1 E–F, 3, 5A–E, 8)

Ancorina alata Dendy, 1924: 298; Pl. V, Fig. 1, 2; Pl. VIII, Fig. 1–7. Ancorina alata, Bergquist (1968: 38; Pl. 5d, 6a, 13f, g; Fig. 12). Ancorina osculifera Dendy, 1924: 300.

Material examined. Three Kings Islands: NIWA 44477: NZOI Stn I378, Great Island, 34.158° S, 172.145° E, intertidal, 23 Nov 1977; NIWA 51230: NIWA Stn KAH9901/33 (Z9681), 34.315° S, 172.818° E, 63 m, 26 Jan 1999; NIWA 62217: NE tip of Great Island, 34.146° S, 172.144° E, 16 m, 14 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6586-S) and the USNM (USNM 1182988); NIWA 52981, NIWA 62155: Great Island, 34.153° S, 172.134° E, 11 m, 14 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6551-G and 0 CDN 6564-T, respectively), and at the USNM (USNM 1182989 and USNM 1182990) respectively; Cape Reinga, North Cape, Northland: NIWA 44246: NIWA Stn Z9243, Cape Reinga, 34.368° S, 172.768° E, 44 m, 28 Feb 1997; NIWA 62218: 2 miles NW of North Cape, 34.381° S, 172.015° E, 80 m, 18 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6664-C) and in the USNM (USNM 1182991); Spirits Bay, Northland: NIWA 52436: NIWA Stn KAH0606/D2, 34.379° S, 172.887° E, depth unknown, 15 May 2005; NIWA 51033: NIWA Stn KAH9901/3 (Z9667), 34.405° S, 172.832° E, 29 m, 24 Jan 1999; NIWA 51124: NIWA Stn KAH9901/24 (Z9676), 34.364° S, 172.841° E, 57 m, 25 Jan 1999; NIWA 51262: NIWA Stn KAH9901/41 (Z9685), 34.376° S, 172.821° E, 49 m, 26 Jan 1999; NIWA 51383: NIWA Stn KAH9901/ 59 (Z9695), 34.367° S, 173.000° E, 89 m, 27 Jan 1999; NIWA 51595: NIWA Stn KAH9901/89 (Z9713), 34.375° S, 172.928° E, 65 m, 29 Jan 1999; NIWA 51618: NIWA Stn KAH9901/91 (Z9715), 34.390° S, 172.986° E, 30 m, 29 Jan 1999; NIWA 51623: NIWA Stn KAH9901/92 (Z9716), 34.361° S, 173.001° E, 100 m, 29 Jan 1999; NIWA 51694: NIWA Stn Z8468, 34.000° S, 172.783° E, 40 m, 1 Jun 1996; NIWA 62259: 34.396° S, 172.999° E, 18 m, 25 Mar 2007; NIWA 62329: 34.438° S, 172.761° E, 19 m, 25 Mar 2007; Cavalli Islands: NIWA 44252: NIWA Stn BG9701, 34.991° S, 173.970° E, 41 m, 3 Mar 1997; Cape Rodney-Okakari Pont Marine Reserve (Goat Island): NIWA 62451: NIWA Stn Z15648, Sponge Garden, 36.260° S, 174.79° E, 18 m, 0 6 July 1997; Great Barrier Island: NIWA 62163: 36.179° S, 175.296° E, 10–17 m, 25 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6794-T) and at the USNM (USNM 1182992); NIWA 62164: 36.349° S, 175.474° E, depth unknown, 7 Jun 2006; NIWA 62165, NIWA 62166: 36.333° S, 175.474° E, depth unknown, 7 Jun 2006; Hauraki Gulf: NIWA 62360: Rakino Island, 36.716 °S, 174.96 °E, 15 m, 8 Jun 1999; Coromandel Peninsula: NIWA 44563: Opito Bay, 36.721 °S, 175.798 °E, depth unknown, 23 Mar 1991; Bay of Plenty: NIWA 44398: NZOI Stn J698, 37.830° S, 176.863° E, 6 m, 10 Oct 1974; East Cape, North Island: NIWA 44222: NIWA Stn Z7092, Pania Reef, Hawkes Bay, 11 m, 6 Feb 1991, collected by Clinton Duffy, Department of Conservation; NIWA 44227: NZOI Stn N901, East Cape, 37.567° S, 178.877° E, 20 m, 27 Feb 1977; Ranfurly Banks, northeast of East Cape: NIWA 75310: TAN1108/213, 37.547° S, 178.893° W, 68–70 m, 30 May 2011; NIWA 75426: TAN1108/233, 37.602° S, 178.896° W, 58–60 m, 31 May 2011; NIWA 75482: TAN1108/239, 37.595° S, 178.866° W, 110–113 m, 0 1 Jun 2011; NIWA 75572: TAN1108/250, 37.519° S, 178.867° W, 106–117 m, 0 1 Jun 2011; NIWA 75605: TAN1108/253, 37.469° S, 178.926° W, 78–86 m, 0 1 Jun 2011; NIWA 75619: TAN1108/268, 37.623° S, 178.893° W, 68–70 m, 0 2 Jun 2011; Gisborne: NIWA 75148: TAN1108/197, Ariel Bank, 38.759° S, 178.355° E, 42–46 m, 29 May 2011; Wellington: NIWA 44462: NZOI Stn C844, 41.638° S, 175.187° E, 88 m, 1 Mar 1962; Marlborough Sounds: NIWA 44479: NZOI Stn P124, 41.043° S, 173.637° E, intertidal, 6 Jun 1977; NIWA 52219: Crail Bay, Pelorus Sound, 41.117° S, 173.950° E, depth unknown, 28 Jul 1999; NIWA 52220: Tawhitinui Reach, Pelorus Sound, 41.033° S, 173.883° E, depth unknown, 22 Jul 1999; NIWA 44223: NIWA Stn Z7195, Port Ligar, Cape Horn, 40.932° S, 173.981° E, 18 April 1991, collected by Department of Conservation; Mernoo Bank and Chatham Rise: NIWA 44226: NIWA Stn W438, 43.238° S, 175.441° E, 78–83 m, 21 Feb 1995; NIWA 44231: NIWA Stn W450, 43.456° S, 175.257° E, 70 m, 22 Feb 1995; NIWA 44234: NIWA Stn W448, 43.240° S, 175.458° E, 74 m, 22 Feb 1995; NIWA 44438: NIWA Stn W436, 43.243° S, 175.439° E, 73–84 m, 20 Feb 1995; NIWA 44015: NIWA Stn W454, 43.451° S, 175.109° E, 126 m, 22 Feb 1995; NIWA 44540: NIWA Stn W437, 43.240° S, 175.434° E, 78 m, 20 Feb 1995. Other material. Ancorina alata: NHMUK 1923.10.1.25 (Holotype), wet subsample from R. N. XXXII.6; NHMUK 1923.10.1.27, wet subsample of R. N. XXXII.12; NHMUK 1923.10.1.28, wet subsample from R. N. XXXII.13; NHMUK 1923.10.1.222, NHMUK 1923.10.1.224, microscope slides from R. N. XXXII. 8: Terra Nova Stn 96, 7 miles east of North Cape, 128 m, British Antarctic (Terra Nova) Expedition, 1910, 16 Jul –24 Sep 1911. Ancorina osculifera: NHMUK 1923.10.1.29, wet subsample from R. N. XXX.10; NHMUK 1923.10.1.225, NHMUK 1923.10.1.226, Terra Nova Stn 96, 7 miles east of North Cape, 128 m, British Antarctic (Terra Nova) Expedition, 1910, 16 Jul –24 Sep 1911, microscope slides from R. N. XXX.10. Ancorina osculifera: NHMUK 1938.8.24.9a, Rangitoto Island, Hauraki Gulf, Auckland, collected by Miss L. B. Moore, microscope slide.

Type locality. North Cape.

Distribution. Three Kings Islands south to Chatham Rise.

Description. Massive sponge, up to 1 m diameter. Two distinct forms: 1) a loaf-shaped to thickly encrusting meandering sponge with bands of small oscules restricted to the apex of lobes or spreading along the tops of broad ridges in shallow troughs (Fig. 1 E). Surface smooth to undulating, never strongly nodular, sometimes corrugated, smooth and granular to the touch, and 2) a bowl-shaped to meandering elongate sponge with a thin, undulating rim that separates two very distinct surfaces, an upper concave exhalent surface which is smooth and perforated by numerous tiny oscules, 2–3 mm diameter, and a lower convex inhalant surface that is bumpy and often shaggy with projecting spicules (Fig. 1 F). The latter form is less common than the former. Texture moderately compressible, slightly flexible. Granular to the touch, interior slightly fleshy but harsh. Colour in life typically shark grey to charcoal, internal colour is tan. Colour in ethanol dark tan, interior beige.

Skeleton. Ectosome is approximately 100 µm deep, with a dense crust of acanthomicrorhabds at the surface, and a dense region of pigmented cells at the surface, as illustrated in Fig. 3. Fine, short, hair-like oxeas are sparsely distributed in the ectosome, and protrude from the surface. Large, stout oxeas are located in the deeper regions of the choanosome and just into the region containing plagiotriaenes. Long thin oxeas surround the plagiotriaenes and stout oxeas that radiate and diverge into brushes at the surface. Anatriaenes may or may not be present in the tracts of oxeas and plagiotriaenes, and vary greatly in abundance and in the size and shape of the cladome. Towards the centre of the sponge stout oxeas are packed in confusion. Acanthomicrorhabds and chiasters are moderately abundantly scattered throughout the choanosome.

Spicules. Megascleres (Fig. 5 A–C) are oxeas I, large, stout, fusiform, with sharply pointed tips, usually slightly curved, occasionally with stylote or strongylote modifications, 2257 (1818–2713) x 55 (35–69) µm; oxeas II, very long and hair-like with finely tapered ends, 1756 (1362–2264) x 11 (6–14) µm (n=10); oxeas III, short and hair-like, 168 (90–244) µm long and about 1–2 µm wide; plagiotriaenes (Fig. 5 A) with a conical rhabdome and sharply pointed clads that recurve towards the tips, rhadome length 2495 (1951–3086) µm, clad length 218 (150– 312) µm, cladome width 334 (244–423) µm; anatriaenes (Fig. 5 B, C), long and very slender, 2314 (1781–2755) µm long, size and shape of cladome variable, 38 (24–54) µm wide.

Microscleres (Fig. 5 D–E) are chiasters (Fig. 5 D) with 4–8 smooth, slender rays that terminate in a cluster of multiple recurved spines, 9 (6–13) µm diameter; acanthomicrorhabds (Fig. 5 E), straight, slightly uneven, acanthose, often centrally or irregularly thickened, gradually tapering towards bluntly rounded ends, 8 (7–11) µm long.

Substrate, depth range, and ecology. Very common in silty harbours and on coastal rocky reefs around northern New Zealand, from the intertidal zone down to 180 m.

Remarks. Uriz’s (2002) diagnosis of the characters that separate Ancorina and Ecionemia, namely, the possession of ‘sanidasters’ in Ancorina and acanthomicrorhabds in Ecionemia, has led us to reassign A. alata to Ecionemia. Ecionemia alata, known in the taxonomic and popular New Zealand literature as A. alata, is one of the most common sponges in New Zealand coastal waters, and is distinctive in both shape and size. Dendy (1924) described another New Zealand species, A. osculifera, noting its similarity to E. alata, but differentiating it on the presence of long, hair-like oxeas (oxeas III in this work) that appeared to replace the anatriaenes in what he would otherwise consider to be E. alata. Dendy noted a difference in the positioning of the oscules, on the tops of flat ridges in A. osculifera (our form 1) as opposed to in the concave surface of bowl-shaped E. alata (our form 2). Bergquist (1968) found specimens that contained both anatriaenes and oxeas III, and synonymised A. osculifera with E. alata, concluding that the two forms of E. alata were the result of habitat differences, with intertidal sponges assuming a rounded massive to lobate form, and deeper water specimens taking a more variable, meandering shape.

Examination of numerous specimens in this work supports Bergquist’s decision to synonymise the two species on the basis of spiculation, but we have found no evidence to support Bergquist’s conclusion that the very clear differences in morphology are a result of habitat differences.