Poliopogon amadou Thomson 1877
Creators: name: Castello-Branco, Cristiana
name: Collins, Allen G.
name: Hajdu, Eduardo
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Hexactinellida
Amphidiscosida
Pheronematidae
Poliopogon
Poliopogon amadou

description: <i>Poliopogon amadou</i> Thomson (1877) (Figs. 2 and 3) Examined Material MNRJ 17629, São Paulo Ridge, Southwest Atlantic (‘Shinkai’ submersible Dive 1335— sample 6(3), Iata Piúna Expedition, 28 29 <i>′</i> 53.88 <i>″</i> S/41 39 <i>′</i> 11.88 <i>″</i> W), 3,060 m depth, coll. A. Augustin, 26.IV.2013. DESCRIPTION. Lophophytous sponge, semi-funnel to fan-shaped body, following <i>Schulze (1887)</i> “leaf rolled up in a semi-funnel, with a concave gastral, and a convex external surface”. Specimen 173 mm long (including 12 mm long basalia), and 67 mm in diameter (adjacent to basalia), compressible and rough (<b>fi</b> g. 2). Basalia composed of broad tufts of anchoring spicules. Brown color in situ and after preservation in ethanol. SKELETON AND SPICULES. Quadrangular framework composed of regular and pinular pentactins, where the latter have their pinular ray piercing the sponge inwards. Basalia with two-toothed smooth anchorates, 371–543 µm wide anchors; smooth monaxons with clavate distal ends (100–229 µm diameter), and sceptres with three-toothed distal ends (1,201–2,946 × 4–10 µm). Dermalia and atrialia consisting of smooth pentactins with conical ends forming quadrangular meshes (sagittal rays, 552–2,619 × 19–29 µm; tangential rays, 368–621 × 19–29 µm); pinular pentactins with pinular rays perpendicular to the plane of the quadrangular meshes (dermal—pinular ray 310–533 × 7–10 µm; tangential rays 77–126 µm; atrial – pinular ray 252–407 × 7–10 µm, tangential rays 58–97 µm). Uncinates in two size categories: macrouncinates (795–3,589 × 4–10 µm), and mesouncinates (76–192 × 1–2 µm). Microscleres include amphidiscs in three size categories: macramphidiscs with smooth shafts (116–261 µm long, umbel 38–72 × 43–77 µm height × width), mesamphidiscs (36–68 µm long, umbel 12–19 × 9–19 µm height × width), and micramphidiscs (21–36 µm long, umbel 7–14 × 7–12 µm length × width). The latter two with spined shafts. Microhexactines (diameter 81–127 µm, ray width 3–5 µm), micropentactines (diameter 74–146 µm, ray width 2–5 µm), rarely microstauractines of similar dimensions, all with spined rays (<b>fi</b> g. 3). Rare hexadiscs. DISTRIBUTION AND ECOLOGY. Former records from the Azores (<i>Thomson, 1873</i>), and the Canary Islands (<i>Thomson, 1877</i>, <i>Schulze, 1887</i>), 2,789–4,022 m deep (<i>Tabachnick &amp; Menshenina, 2002</i>). This is the <b>fi</b> rst <b>fi</b> nding of the species in the South Atlantic, where it is thus far only known from the São Paulo Ridge (SW Atlantic) (present paper), at 3,060 m depth. The single specimen collected was growing on basaltic rock with other sponges likely of the same species, albeit in very low densities. No epibiontic macro- or megafauna could be seen from the images obtained (Fig. 2). Remarks The single specimen collected by the Iata Piuna expedition matches the original description of <i>Thomson (1877)</i> and redescription by <i>Tabachnick &amp; Menshenina (2002)</i>. The latter authors mentioned that whereas macramphidiscs are clearly separable from the smaller amphidiscs, separation of second and third categories as mesamphidiscs and micramphidiscs is not always straightforward. It is not clear to us whether <i>Tabachnick &amp; Menshenina (2002)</i> were referring to every specimen as a rule, the holotype included. Regardless, in our material the three categories were clearly separable, if not entirely on the basis of dimensions, but surely when the micromorphology of these microscleres was taken into account. The rare hexadiscs seen in our specimen had previously been reported from a single specimen from the Great Meteor Bank (29 58 <i>′</i> 51.560 4 <i>″</i> N/28 29 <i>′</i> 12.645 6 <i>″</i> W, 2,480–2,550 m depth; <i>Tabachnick &amp; Menshenina, 2002</i>).
description: Published as part of <i>Castello-Branco, Cristiana, Collins, Allen G. &amp; Hajdu, Eduardo, 2020, A collection of hexactinellids (Porifera) from the deep South Atlantic and North Pacific: new genus, new species and new records, pp. e 9431 in PeerJ 8</i> on pages 4-6, DOI: 10.7717/peerj.9431, http://zenodo.org/record/4624210
description: {"references": ["Thomson CW. 1877. The voyage of the \" Challenger \": the Atlantic, a preliminary account of the general results of the exploring voyage of H. M. S - \" Challenger \" during the year 1873 and the early part of the year 1876. Vol. 1. London: Macmillan and Co., 424.", "Schulze FE. 1887. Report on the Hexactinellida collected by H. M. S. ' Challenger' during the years 1873 - 1876. Report on the scienti fi c results of the voyage of H. M. S. ' Challenger ', Zoology 21: 1 - 514.", "Thomson CW. 1873. The depths of the sea. London: Macmillan and Co., 527.", "Tabachnick KR, Menshenina LL. 2002. Family Pheronematidae Gray, 1870. In: Hooper JNA, Van Soest RWM, eds. Systema Porifera. A guide to the classification of sponges. Vol. 2. New York: Kluwer Academic / Plenum Publishers, 1267 - 1280."]}