Penares orbis sp. nov.

(Fig. 30–33; Table 10)

Material examined. Holotype — NIWA 81643, NIWA Stn TAN1206/40, Kermadec Ridge, 36.446° S, 177.837° E, 1100–1170 m, 18 Apr 2012 . Paratypes — NIWA 81648, NIWA Stn TAN1206/39, Kermadec Ridge, 36.452° S, 177.846° E, 1030–1255 m, 18 Apr 2012; NIWA 62492, NIWA Stn TAN1104/18, Hikurangi Plateau, 36.450° S, 177.840° W, 836–840 m, 4 Mar 2011 . Other material. Three Kings Ridge: NIWA 43892, NZOI Stn Z9025, 31.980° S, 174.265° E, 677–1680 m, date unknown; NIWA 43894, NZOI Stn U 594, 30.335° S, 172.993° E (International Waters), 406 m, 7 Feb 1988 .

Bay of Plenty: NIWA 52486, NIWA Stn TAN0413/177, 37.312° S, 177.066° E, 550–725 m, 16 Nov 2004 .

Kermadec Ridge: NIWA 81645, NIWA Stn TAN1206/39, 36.452° S, 177.846° E, 1030–1255 m, 18 Apr 2012; NIWA 81653, NIWA Stn TAN1206/95, 36.451 °S, 177.840 °E, 840–872 m, 24 Apr 2012 .

Type locality. Southern Kermadec Ridge, New Zealand .

Distribution. Found in northeastern New Zealand; 406–1680 m (Figure 33).

Description. Morphology is a small, amorphous sponge comprised of several lobes (Figure 30A), holotype is growing around dead coral branches. The holotype is 40 mm long × 30 mm wide × 15 mm high. Surface is crum- pled, uneven with irregular, shallow depressions all over the sponge, scratchy to the touch. A few large oscules, around 3 mm diameter, are present at the apex of the lobes (Figure 30C). Very small, uniporal pores, not visible to the naked eye (130–150 µm in diameter), are densely scattered over the surface of the sponge (Figure 30D). Texture is very hard, incompressible. Colour in ethanol is cream, interior is beige.

Skeleton. Cortical skeleton is 300–500 µm thick and consists of a densely packed layer of tangential microxeas (Figure 31A). Choanosomal skeleton has a layer of abundant dichotriaenes present, cladomes positioned extend beyond the surface of the sponge (Figure 30B) as well as being positioned directly below the cortex (Figure 31C). Spherasters are scattered in a band <100 µm thick just below the cortex/choanosome boundary (Figure 31B) but are rarely present in the rest of the choanosome. Megascleres are a mixture of oxeas, tylostyles and tylostrongyles, which are present in the inner choanosome. Microxeas are very densely packed throughout the choanosome (Figure 31D). Small, round, spherules are scattered throughout the choanosome.

Spicules (Figure 32; Table 10). Megascleres —tylostyles (Figure 32A) are moderately long, slightly curved and of greatly varying width from thin to quite stout; 2376 (1553–3293) × 63 (21–123) µm (n = 56). Oxeas (Figure 32C) are a similar size to tylostyles; 2378 (1117–3533) × 51 (16–143) µm (n = 66). Tylostrongyles (Figure 32B) are straight and stout; 1997 (1175–2688) × 72 (38–110) µm (n = 21). Dichotriaenes (Figure 32D) have a short rhabdome that often has a tylote or bluntly rounded tip (Figure 32E). Clads are broad, flattened and leaf-like. Protoclads are much shorter than deuteroclads (Figure 32F). One or more clads may be trifurcate (Figure 32G). The cladome is approximately twice as wide as the rhabdome length; 645 (390–984) µm long × 1046 (571–1660) µm wide (n = 75).

Microscleres —microxeas (Figure 32H) are variable in size with sharply pointed or slightly rounded tips. Some are faintly centrotylote; 97 (33–207) × 6 (3–9) µm (n = 128). Spherules (Figure 32I) are small and completely smooth; 11 (5–23) µm in diameter (n = 60). Spherasters (Figure 32J) are very small with numerous smooth, conical rays; 10 (7–13) µm in diameter (n = 65).

Etymology. Named after the smooth spherules present in this species ( orbis, globe; Latin).

Remarks. The combined presence of spherules and spherasters differentiates P. orbis sp. nov. from all other Penares species. The presence of either spherules or spherasters in species of Penares is relatively unusual, but not unprecedented. Three species ( P. dendyi (Hentschel, 1912) from Indonesia, P. metastrosa from Japan (Lebwohl, 1914), and P. sphaera (Lendenfeld, 1907) from South Africa) possess spherules but no spherasters, while P. micraster Lévi, 1993 from New Caledonia possesses spherasters but no spherules.