Acanthancora equiformis Sim-Smith &amp; Hickman &amp; Kelly 2021, sp. nov.
Creators: name: Sim-Smith, Carina
name: Hickman, Cleveland
name: Kelly, Michelle
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Poecilosclerida
Hymedesmiidae
Acanthancora
Acanthancora equiformis

description: <i>Acanthancora equiformis</i> sp. nov. (Fig. 20) <b>Material examined.</b> <i>Holotype —</i> MCCDRS9456, Nameless Island, 0.67° S, 90.586° W, 8 m, 9 Aug 2003. <b>Type locality.</b> Nameless Island. <b>Habitat and distribution.</b> Only known from the type locality. Found growing in a small recess on a vertical rock wall; 8 m. <b>Description.</b> Very thinly encrusting sponge, less than 1 mm thick, densely covered in small oscules and ostia that are flush with the surface. Faint asterose drainage canals are visible on the surface. Colour in life is pale grey with tinges of white, colour in ethanol is light beige (Fig. 20A). Texture is soft. <b>Skeleton.</b> Unknown, specimen is too thin to section, but assumed to be consistent with the skeletal architecture in species included in this genus, as diagnosed above. <b>Spicules.</b> <i>Megascleres—</i> smooth strongyles with slightly inequiended tips, one tip being more bulbous than the other, sometimes faintly polytylote; 160 (125–182) × 4 (3–6) µm (n = 20) (Fig. 20C–D). Acanthostyles, strongly tapered with a prominent spined head; 84 (71–91) µm long (n = 20) (Fig. B). <i>Microscleres—</i> heavily spined isochelae; 20 (17–22) µm long (n = 20) (Fig. 20E). <b>Etymology.</b> Named for the form of the microscleres which resemble prancing horses (Latin adjective agreeing with <i>Acanthancora</i> = ‘horse-shaped’). <b>Remarks.</b> Only one species of <i>Acanthancora</i> has been described from the eastern Pacific: <i>A. cyanocrypta</i> (Laubenfels, 1930) from California. <i>Acanthancora equiformis</i> <b>sp. nov.</b> differs from <i>A. cyanocrypta</i> in that the latter species is blue in life, possesses two size classes of acanthostyles, and has smaller chelae (10–15 µm; measurements from Van Soest 2002a) with blunt spines. <b>Genus <i>Hemimycale</i> Burton, 1934</b> <b>Diagnosis.</b> Thickly encrusting to massive, with striking and characteristic areolated porefields; skeleton of plumose columns of slightly inequiended strongyles, which are probably derived from tornotes; styles and oxeas may also be present. The choanosomal columns fan out near the surface and strengthen the raised porefields; no microscleres other than raphides (emended Van Soest, 2002 a and Huguenin <i>et al.</i> 2018).
description: Published as part of <i>Sim-Smith, Carina, Hickman, Cleveland &amp; Kelly, Michelle, 2021, New shallow-water sponges (Porifera) from the Galápagos Islands, pp. 1-71 in Zootaxa 5012 (1)</i> on pages 44-45, DOI: 10.11646/zootaxa.5012.1.1, http://zenodo.org/record/5158062
description: {"references": ["De Laubenfels, M. W. (1930) The Sponges of California. (Abstracts of dissertations for the degree of Doctor of Philosophy). Stanford University Bulletin, 5, 24 - 29.", "Van Soest, R. W. M. (2002 a) Family Hymedesmiidae Topsent, 1928. In: Hooper, J. N. A. &amp; Van Soest, R. W. M. (Eds.), Systema Porifera: A Guide to the Classification of Sponges. Vol. 1. Kluwer Academic / Plenum Publishers, New York, New York, pp. 575 - 593. https: // doi. org / 10.1007 / 978 - 1 - 4615 - 0747 - 5 _ 62", "Burton, M. (1934) Sponges. Scientific Reports of the Great Barrier Reef Expedition 1928 - 29, 4, 513 - 621.", "Schuster, A., Cardenas, P., Pisera, A., Pomponi, S. A., Kelly, M., Worheide, G. &amp; Erpenbeck, D. (2018) Seven new deep-water Tetractinellida (Porifera: Demospongiae) from the Galapagos Islands - morphological descriptions and DNA barcodes. Zoological Journal of the Linnean Society, 184 (2), 273 - 303. https: // doi. org / 10.1093 / zoolinnean / zlx 110"]}