Dysidea kenkriegeri 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; Dictyoceratida; Dysideidae; Dysidea; Dysidea kenkriegeri; Gulf of Alaska; Sedanka; Alaska; Aleutian Islands
• Online Access: https://zenodo.org/record/5617505; https://doi.org/10.5281/zenodo.5617505

Dysidea kenkriegeri n. sp. (Fig. 17) Material examined. Holotype: ZSM 20150393, collected by Dave Somerton with a research survey bottom trawl (haul # 15) aboard the FV Alaska Provider; 1 June 2013, 93 m depth, 10.7 km south of Sedanka Island, east end of Unalaska Island, eastern Aleutian islands, Gulf of Alaska (53 ° 36.6380 ' N, 166 °12.4800' W). Water temperature = 4.5 °C. Complete specimen in ethanol. Description. Habitus: The sponge consists of a group of agglutinated tubes starting from a single stalk with maximum height of 9.7 cm (Fig. 17 A). The stalk is 1 cm in diameter with a length of 1.8 cm before the sponge widens to a central area where seven tubes diverge. Single tubes are 0.8 to 1.4 cm in diameter with lengths between 2.7 and 4 cm. Thickness of the tube walls varies from 2–4 mm. The consistency of the tubes is soft and elastic while the stalk is hard and only slightly elastic. The color is light brown to beige and the surface is smooth and velvety, openings are recognisable at the top the tubes only (Figs. 17 B & C). Skeletal structure: The choanosome consists of a meshwork of spongin fibers loaded with foreign spicules and sediment, mesh-sizes variable, 130–880 µm. Sections perpendicular to the surface reveal smaller meshes, approximately 100–200 µm in diameter, in an area from the surface down to 300 –- 500 µm into the interior of the sponge, then larger meshes of mostly elongated rectangular shape dominate (Fig. 17 D). Ascending spongin fibers are 120–250 µm in diameter, connecting fibers are 40–150 µm (Figs. 17 E & F). Spongin fibers ascend obliquely to the surface. The ectosome is also a reticulation of spongin fibers cored by foreign particles and connecting the fibers reaching the surface. Ectosomal fibers measure 35–80 µm in diameter, forming a network with diameters of 50–350 µm. Discussion. Sponges of the orders Dictyoceratida and Dendroceratida are mainly known from warmer seas. Our record of a species of Dysidea is the first for the order Dictyoceratida from Alaska. There are ...