Artemisina flabellata 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; Microcionidae; Artemisina; Artemisina flabellata; Bering Sea; Petrel Bank; Aleutian Islands
• Online Access: https://zenodo.org/record/5617479; https://doi.org/10.5281/zenodo.5617479

Artemisina flabellata n. sp. (Figs. 8 & 9, Table 3) Material examined. Holotype: ZSM 20150387, collected by Jay Orr with a research survey bottom trawl (haul # 135) from the FV Ocean Explorer; 11 July 2012, 99 m depth, Petrel Bank, central Aleutian Islands, Bering Sea (52 ° 15.9960 ' N, 179 ° 54.0060 ' E). Water temperature = 4.3 °C. Complete specimen in ethanol. Description. Habitus: Large, light brown to gold colored, fan-shaped to flabellate sponge, starting from an almost circular base with a maximum diameter of 7 cm and a height of 26.5 cm, the upper rim approximates a quarter-circle, 25.8 cm in width (Fig. 8 A). The thickness of the blade is quite variable, the thickest part is 9 cm while other parts are less than 1 cm in thickness. There is a hole in the center of the blade, possibly from tissue necrosis (Fig. 8 B). No oscules are visible. The consistency of the base is hard and inelastic, softer and more elastic but, still resilient, towards the top. Skeletal structure: The ectosome is a relatively thick veneer of densely packed thin ectosomal styles primarily in a tangential arrangement, single bundles of ectosomal styles may stand perpendicular to the surface and consequently the thickness varies between 200 and 700 µm. The choanosome is halichondroid and consists of vague tracts with many spicules in between. Plumose tracts are irregular and there are many spicules in between. Spicules: are thick choanosomal styles, finely spined apically, 648–1630 x 25–33 µm (Figs. 8 C & E), occasionally strongylote or weakly microspined all over, apically spined ectosomal styles, 453– 1152 x 9–16 µm (Figs. 8 D & E), small acanthostyles, 157–248 x 15–18 µm (Fig. 8 F), cleistochelae with a peculiar central plate on the shaft and the alae fused or open with a small gap, 13–18 µm (Figs. 9 A & B), thin, smooth toxa, 90–1150 µm (Fig. 9 C). Discussion. The skin-like ectosome and halichondroid choanosome warrant assignment in the genus Artemisina. Again we compare Artemisina flabellata n. sp. with eight ...