Igernella notabilis (Duchassaing & Michelotti, 1864)

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 18

Igernella notabilis (Duchassaing & Michelotti, 1864)

Figures 9 a–c

Euryades notabilis Duchassaing & Michelotti, 1864: 106 , pl. 25 fig.3.

Darwinella joyeuxi Topsent, 1889: 46 , fig. 11; De Laubenfels 1948: 170, fig. 28.

Igernella joyeuxi ; Topsent 1905, clxxxviii, fig. 3; Boury-Esnault 1973: 287.

Igernella notabilis ; Van Soest 1978: 76, Pl. XV fig. 1, text-fig. 1; Pulitzer-Finali 1986: 181, fig. 87; Uriz & Maldonado 1996: 154, fig. 2; Lehnert & Van Soest 1998: 97; Moraes 2011: 204, 4 unnumbered figs; Muricy et al. 2011: 55; Rützler et al. 2014: 96 .

Material examined. RMNH Por. 9937, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 63, 7.5833°N 57.0667°W, depth 71 m, sandy bottom, 31 August 1970 .

Description. Lobate conulose sponge, with large apical oscules. The sample contains seven fragments ( Fig. 9 a), each about 3 cm high and 1–1.5 cm in diameter ( Fig. 9 a1), assumed to be from a single larger specimen. Oscules about 0.5 cm in diameter, conules 2–4 mm apart. Consistency soft, easily torn.

Skeleton. A rectangular spongin reticulation ( Fig. 9 b) of thicker ascending fibers (up to 160 µm in diameter), and thinner connecting fibres, up to 60 µm in diameter. Meshes large, 400–1000 µm in size. Fibers laminated and pithed, lightly cored by sand grains and broken spicules. Horny spicules ( Fig. 9 c) not common, only triactines were observed, actines 310–700 x 16–25 µm.

Distribution and ecology. Guyana Shelf, Virgin Islands, Mexican Caribbean, Curaçao, St. Eustatius, Puerto Rico, Jamaica, Anguilla, Belize, NE Brazil, mostly on reefs, but also known from the fore reef slope and sandy bottom, 4–71 m depth (previously down to 52 m).

Remarks. The specimens from the Guyana Shelf are closely similar to the type material and other recently described specimens (cf. Van Soest 1978; Uriz & Maldonado 1996). Differences with these specimens are that the present fibers are comparatively thin and there are only few horny spicules. The Cape Verdian species Igernella vansoesti Uriz & Maldonado, 1996 is reported to occur in the Gulf of Mexico ( Uriz & Maldonado 1996) (p. 159), but this needs further verification. The shape of Igernella vansoesti is clearly different from the present fragments.

Figures

FIGURE 9. Igernella notabilis (Duchassaing & Michelotti, 1864), RMNH Por. 9337, a, fragments (scale bar = 1 cm), a 1, one of the fragments enlarged (scale bar = 1 cm), b – c, light microscopic images, b, peripheral skeleton, c, horny spicule.