Polymastia tenax Pulitzer-Finali, 1986

Ugalde, Diana, Fernandez, Julio C. C., Gómez, Patricia, Lôbo-Hajdu, Gisele & Simões, Nuno, 2021, An update on the diversity of marine sponges in the southern Gulf of Mexico coral reefs, Zootaxa 5031 (1), pp. 1-112 : 58-59

Polymastia tenax Pulitzer-Finali, 1986

Tables 6, 7; Figs. 53A–H , 58H

Synonymy and references: Polymastia tenax Pulitzer-Finali (1986: 89) , Boury-Esnault (1987: 55), Vacelet (1990: 22), Lehnert (1993: 63), Lehnert (1998: 80), Pérez et al. (2017: 12), and van Soest (2017: 122).

Type locality. Dominican Republic .

Material examined. CNPGG-2253, Triangulo Oeste reef (20.96412°N, 92.30193°W), 9 m depth, coll. Oscar Bocardo, 09 September 2017 ; CNPGG-2257, Triangulo Oeste reef (20.95864°N, 92.30453°W), 17.4 m depth, coll. Oscar Bocardo, 10 September 2017 ; CNPGG-2258, Triangulo Oeste reef (20.95864°N, 92.30453°W), 8.3 m depth, coll. Oscar Bocardo, 10 September 2017 ; CNPGG-2286, Triangulo Este reef (20.89108°N, 92.23992°W), 20 m depth, coll. Oscar Bocardo, 12 September 2017 ; CNPGG-2292, Banco Obispo Norte reef (20.4946°N, 92.20378°W), 14.8 m depth, coll. Oscar Bocardo, 13 September 2017 .

Description. Massive habit with lobate conical papillae ( Fig. 58H ); the larger specimen with 4 × 3 × 2.5 cm at the base, and papillae with 0.8 cm in diameter, 0.1 to 0.5 cm high. The surface is smooth, slightly wavy, and without visible pores. Oscules at the top of each papillae, up to 0.6 cm in diameter. Both brown and whitish colors show up in vivo, light brown when preserved in ethanol. The consistency is hard, almost incompressible.

Skeleton. Ectosomal region formed by a dense palisade of smaller tylostyles perpendicular to the surface ( Fig. 53A ). The choanosomal region is a confused mass of spicules ( Fig. 53B ), sometimes with style tracts, 30–100 µm thick. Larger tylostyles scattered in criss-cross position deep in the choanosome ( Fig. 53C ).

Spicules. Megascleres: Subtylostyles I, Large straight to slightly curved or sinuous, fusiform, and smooth, with a blunt or tyle-shaped base ( Fig. 53E–F ); 500–738 (97.2)–870/7.5–13.3 (2.5)–16.8 µm and base/tyle 7–8.9 (1.8)–14.5 µm. Subtylostyles II, stout, straight, fusiform, and smooth ( Fig. 53G ); 330–437.3 (45.6)–490/7.2–19.8 (5.4)–25 µm and tyle 5–8.5 (2.1)–12 µm. Subtylostyles III, smaller and thinner than the two previous categories ( Fig. 53H ); 160–206.7 (34.8)–290/2.4–4.9 (1.2)–7.2 µm and tyle 2.4–4.4 (1.1)–6.5 µm.

Distribution. Mexico (current records), Greater Antilles ( Pulitzer-Finali 1986; Boury-Esnault 1987).

Remarks. Polymastia tenax had not been recorded from the GoM before. Therefore, our specimens are the first record in the area. The type material of P. tenax is described as cushion-shaped with open papillae, with the same skeletal structure described herein. The spicule measurements are quite similar to the present material: styles 630–770/11–14 µm, large subtylostyles 320–420/18–30 µm, and small subtylostyles 130–330/2.5–9 µm (Pulitzer- Finali 1986).

Figures

FIGURE 53. Polymastia tenax Pulitzer-Finali, 1986 (CNPGG-2253), skeleton and spicules: A. transversal section of the skeleton of the ectosomal region, small tylostyles perpendicular with the surface making a hispid surface; B. transversal section of the skeleton, choanosomal region with slender tylostyles in criss-cross, detail zoomed in; C. transversal section of skeleton; D. general view of spicules; E. Subtylostyle I; F. Subtylostyle I with a tyle present in the axis; G. Subtylostyle II with fusiform appearance; H. Subtylostyles III. Scale bars: A–B = 100 µm; C = 250 µm; D = 100 µm; E–H = 50 µm.

FIGURE 58. In situ photographs of species analyzed in the present study: A. Acarnus innominatus Gray, 1867 (CNPGG-2393); B. Monanchora arbuscula (Duchassaing & Michelotti, 1864) (CNPGG-2204); C. Strongylacidon bermuda (de Laubenfels, 1950) (CNPGG-2170); D. Desmapsamma anchorata (Carter, 1882) (CNPGG-2443); E. Iotrochota arenosa Rützler, Maldonado, Piantoni & Riesgo, 2007 (CNPGG-2422); F. Mycale (Mycale) laevis (Carter, 1882) (CNPGG-2273); F. Mycale (Arenochalina) laxissima (Duchassaing & Michelotti, 1864) (CNPGG-2267); H. Polymastia tenax Pulitzer-Finali, 1986 (CNPGG-22587); I. Scopalina ruetzleri (Wiedenmayer, 1977) (CNPGG-2183); J. Svenzea cristinae Alvarez, van Soest & Rützler, 2002 (CNPGG- 2474); K. Svenzea flava (Lehnert & van Soest, 1999) (CNPGG-2288); L. Svenzea tubulosa (Alcolado & Gotera, 1986) (CN- PGG-2272), surface detail zoomed in (arrow indicates white channels in the choanosomal region). Scale bars, A–L = 1 cm.