Ancorina diplococcus Dendy 1924
Creators: name: Kelly, Michelle
name: Sim-Smith, Carina
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Astrophorida
Ancorinidae
Ancorina
Ancorina diplococcus

description: Ancorina diplococcus (Dendy 1924)
(Fig. 1 A, 3, 4A–C, 8; Table 1)
Ancorina progressa Lendenfeld, 1907 var. diplococcus Dendy, 1924: 297. Ancorina progressa, Bergquist (1968: 40).
Material examined. NIWA 43925: NZOI Stn I808, continental shelf off Ninety Mile Beach, Northland, 35.042° S, 172.867° E, 192 m, 18 Jun 1981; NIWA 62048: 17 miles west of Pandora Bank and 31 miles west of Ninety Mile Beach, Northland, 34.648° S, 172.220° E, RV Kaharoa, 198–208 m, 21 Apr 1999, additional vouchers are in the CRRF reference collection (0 CDN 6733-C) and at the USNM (USNM 1182984). Other material. Ancorina progressa var. diplococcus: NHMUK 1923.10.1.217, NHMUK 1923.10.1.218, NHMUK 1923.10.1.219, Terra Nova Stn 90, Three Kings Islands, 183 m, British Antarctic (Terra Nova) Expedition, 1910, 16 Jul –24 Sep 1911, microscope slides from holotype R. N. L. 1a; Ancorina progressa, Valdivia and Gazelle Lendenfeld 0 8.29.130, 0 8.29.131, and 0 8.29.133.
Type locality. Three Kings Islands.
Distribution. Three Kings Islands, Pandora Bank, west of Ninety Mile Beach, Northland.
Description. Small sponge composed of rounded lobes, 30–40 mm diameter (Fig. 1 A). Texture is compressible but not easily torn. Surface is rough to the touch, interior is very spiculose. Colour in life is purplish brown, interior is tan. Colour in alcohol is yellowish beige. Ectosome is approximately 1 mm thick and clearly differentiated from the choanosome by the lighter interior. No oscules or ostia visible with the unaided eye.
Skeleton. Ectosome is 1000–1300 µm deep and clearly differentiated from the underlying choanosome (Fig. 3). The ectosome is translucent with a dense layer of fibrillar collagen near the lower boundary, 300–600 µm thick, and a much thinner layer of collagen at the surface, 50 µm thick. The ectosome is reinforced with dichotriaenes that radiate in dense brushes, their cladomes uppermost at the surface, the end of the rhabdomes just entering the choanosome. Non-euasterose microscleres form a thin, well defined crust at the surface of the sponge, and are very sparsely scattered throughout the choanosome. Large oxeas are restricted to the choanosome where they form untidy paratangential or oblique bundles. Large oxyasters are very abundant in the choanosome.
Spicules. Megascleres (Fig. 4 A, Table 1) are oxeas, large, stout, usually slightly curved with sharply pointed ends, 2031 (1625–2733) µm; dichotriaenes (Fig. 4 A) with a thick conical rhabdome, slightly swollen below the cladome, and wide cladome. The protoclad protrudes at a 45° angle from the shaft and the deutroclad is horizontal to the shaft, rhabdome length 1290 (950–1650) µm, cladome width 575 (375–774) µm; plagiotriaenes sit just below the ectosome/choanosome boundary are possibly immature dichotriaenes, rhabdome length about 600 µm, cladome width 170 (150–200) µm.
Microscleres (Fig. 4 B–C, Table 1) are oxyasters (Fig. 4 B), 4–8 large rays that are very sparsely acanthose, 19 (13–28) µm diameter. A small number of more compact, more heavily-rayed, slightly smaller oxyasters were seen in all specimens, but these were not abundant enough to separate out as a second size category with confidence; sanidasterhabds (Fig. 4 C), acanthose, irregularly and heavily spined, frequently with a central restriction, producing a dumbbell shape, 5 (3–6) µm long (Table 1).
Substrate, depth range and ecology. Incorporates coarse sand and rubble between lobes; found between 183– 208 m.
Remarks. Dendy (1924) assigned a Three Kings Islands sponge to the South African species Ancorina progressa, currently considered to be a species of Stryphnus in World Porifera Database (van Soest 2011b). Dendy listed several differences between the type of A. progressa and the Three Kings specimen (Table 1), including the smaller dimensions of the microscleres and oxeas, the larger size of the dichotriaenes (almost double the length), and the less spiny, dumbbell-shape of the microscleres in the latter. He named the variety thus distinguished A. progressa var. diplococcus. Bergquist (1968) denounced the varietal distinction A. progressa var. diplococcus as being invalid, because she believed that “spicule size and microsclere morphology vary so greatly within Choristid species that varietal distinctions on these grounds alone are insufficient”. Apart from the comment about the considerable variation in spicule size, we disagree with Bergquist’s conclusions because, as we show here, there are considerable differences between the two species (Table 1). The key difference between S. progressa and A. diplococcus is the shape of the microscleres in the former, which are true sanidasters and amphiaster-like microscleres (now called amphisanidasters, see below). Moreover, examination of Lendenfeld’s slide material confirms that the skeleton of the former is oblique to the surface, not radial, and the ectosome is diaphanous, two key characters that define the genus Stryphnus.
Ancorina diplococcus was initially thought to be a species of Ecionemia, rather than Ancorina, because the dumbbell-shaped sanidasterhabds are similar in shape to the microrhabds of Ecionemia (See Fig. 5), but these have acanthose spines, rather than simply being roughened. However, the possession of large oxyasters that pack the choanosome in A. diplococcus, and the possession of a conspicuous, clearly differentiated, semi-fibrous ectosome, all features absent in Ecionemia, confirm affinity with the genus Ancorina. Although A. diplococcus has a conspicuous ectosome, it is not diaphanous as in species of Stryphnus, and it lacks the true sanidasters and amphisanidasters that charaterise species in this genus.
description: Published as part of Kelly, Michelle & Sim-Smith, Carina, 2012, A review of Ancorina, Stryphnus, and Ecionemia (Demospongiae, Astrophorida, Ancorinidae), with descriptions of new species from New Zealand waters, pp. 1-47 in Zootaxa 3480 on pages 5-8, DOI: 10.5281/zenodo.282353