Megaciella lobata Lehnert & Stone, 2015, n. sp.

• Main Authors: Lehnert, Helmut, Stone, Robert P.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Porifera; Demospongiae; Poecilosclerida; Acarnidae; Megaciella; Megaciella lobata; Bering Sea; Kiska; Kiska Island; Aleutian Island; Aleutian Islands
• Online Access: https://zenodo.org/record/5617462; https://doi.org/10.5281/zenodo.5617462

Megaciella lobata n. sp. (Figs. 3 & 4, Table 2) Material examined. Holotype: ZSM 20150382, collected by Jay Orr with a research survey bottom trawl (haul # 166) from the FV Ocean Explorer; 17 July 2012, 91 m depth, 2.1 km north of western Kiska Island, western Aleutian Islands, Bering Sea (51 ° 59.5740 ' N, 177 °23.0100' E). Water temperature = 4.3 °C. Complete specimen in ethanol. Description. Habitus: This is a small, brown-colored sponge of firm, only slightly elastic consistency. It has an almost circular outline where several lobes radiate from a center (Fig. 3 A). The lobes are 0.5–2 cm in thickness and up to 2 cm long, starting from a common center, 3.5 x 4.4 x 5.3 cm. Lobes may be partially fused. The surface is hispid, due to projecting spicules of choanosomal spicule tracts (Fig. 3 B). Skeletal structure: The ectosome is a thin membrane and contains scattered anisotylotes with microspined bases and microscleres (Fig. 3 C). In the choanosome, plumose tracts, cored by smooth styles (Fig. 3 D) and echinated by acanthostyles (Fig. 3 B & E), ascend to the surface with the end of the tracts as the cause of the hispid surface. Spicules: Ectosomal anisotylotes have microspined ends, one end more inflated, the other often looking broken but, upon closer examination is complete due to micro-spination, 355–508 x 4–6 µm (Fig. 3 F). Coring the tracts are single, long smooth styles, mostly broken in spicule preparations, 1056–1645 x 19–32 µm (Fig. 3 E). Choanosomal styles, varying from completely smooth or with slightly microspined bases only, to microspined areas at both ends of the style, 735–928 x 42 –55 µm (Fig. 3 D), acanthostyles, 440–710 x 42 –53 µm (Fig. 4 A). Microscleres are toxa in two categories: long, thin toxa, 130–720 µm (Fig. 4 C) and short, thicker toxa, 29–47 µm (Fig. 4 B) and palmate isochelae, 22–47 µm (Fig. 4 D). Discussion. The WPD currently recognises 14 species of Megaciella including two species previously described from the Aleutian Island Archipelago region (Lehnert et al., 2006 b; ...