Spongosorites beringensis Lehnert & Stone 2017, n. sp.
Spongosorites beringensis n. sp. (Fig. 4; Table 2) Material examined. Holotype. ZSM 20170014, whole specimen in ethanol, collected by Jerry Hoff with a research survey bottom trawl from the FV Cape Flattery; 19 July 2016, 959 m depth, 50 km SSE of Cascade Point (St. George Island, Pribilof Islands),...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2017
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| Online Access: | https://zenodo.org/record/6049677 https://doi.org/10.5281/zenodo.6049677 |
| Summary: | Spongosorites beringensis n. sp. (Fig. 4; Table 2) Material examined. Holotype. ZSM 20170014, whole specimen in ethanol, collected by Jerry Hoff with a research survey bottom trawl from the FV Cape Flattery; 19 July 2016, 959 m depth, 50 km SSE of Cascade Point (St. George Island, Pribilof Islands), Pribilof Canyon, eastern Bering Sea (56°07.368´N, 169°15.768´W). Bottom water temperature = 2.9 °C. Description. Spongosorites beringensis is a massively encrusting sponge. The broader side of the sponge (Fig. 4A) has an almost circular outline, 4.7 cm in diameter in one plane but is more flattened, only 2 cm in diameter, when observed from the side. It has a smooth surface which is irregularly folded with rounded, elongated elevations and narrow depressions in between, somewhat resembling the surface of a brain. The colour is light brown to beige in ethanol, and the consistency is firm, only slightly compressible before breaking. There are no oscules visible. The sponge has a smooth surface. The ectosome contains oxeas of all sizes arranged tangentially but, without order within the relatively thick tangential layer. In sections perpendicular to the surface this ectosomal layer is easily recognizable by the unaided eye and differs from the choanosome by a somewhat lighter colour. The thickness of this ectosomal layer varies between 0.25–2.0 mm. The choanosome also contains oxeas of all sizes arranged in tracts and in confusion between the tracts, as usual for the family. Single choanosomal spicule tracts run into the ectosomal layer and attach choanosome and ectosome. Megascleres. Small oxeas, 125–272 x 4–8 µm (Figs. 4B & C), large oxeas, 460– 1690 x 10–25 µm (Fig. 4C). There are occasional styles in both spicule categories. Discussion. The ectosomal tangential arrangement of oxeas, the presence of oxeas in a wide size range and the otherwise confused arrangement of spicules leave no doubt of the assignment to Halichondriidae within the Suberitida. We ruled out assignment to Halichondria because there is always ... |
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