Morphological description (show/hide)
| Mass of branching and anastomosing tubes, 5x3x2cm in size. The tubes anastomose in the proximal part of the cormus near the base, but become unified, only partly branching, in the distal part. Tubes have a terminal osculum with about 5 mm diameter at the osculum. In parts of the cormus the terminal tubes are erect, unbranched and aligned side-by-side, with their cortex partially grown together. | | white | | brownish | | One terminal large oscule at the distal end of each tube, with the same diameter as the tube. | | Soft | | No surface ornamentation | | With an inarticulated skeleton supported by the apical actines of sub-atrial sagittal tetractines and nail-shaped triactines. Nail-shaped triactines pointing with their ÔunpairedÕ actines towards the cortex, their distal part sometimes penetrating the cortical tangential layer of sagittal triactines. The unpaired actines of the sub- atrial triactines do not extend to the cortex. The atrial skeleton is formed by sagittal tetractines with their curved free actines pointing towards and into the atrium. | | A distinct cortex of tangentially arranged sagittal triactines and perpendicularly arranged microdiactines. | | Cortical sagittal triactines are thick, with more-or-less cylindrical actines. Paired actines have a size of 228-(294.7)-343 um, unpaired actines 214-(308.3)-370 um, and a maximum thickness of 15-(27.4)-40 um. Choanosomal nail-shaped triactines (with strongly reduced paired actines) are 144-(234.6)-343 um long and_4-(7.3)-12 um thick. Subatrial sagittal tetractines delimit the choanosome towards the atrial skeleton with their regular basal triradiate system (30-(52.4)-79 um), and their elongated apical actine (133-(260)-320 um long) forms the proximal part of the choanoskeleton. All actines are more-or-less cylindrical, whereas the longer apical actine has a conical tip, with a maximum thickness 3-(8.8)-13 um. Atrial tetractines are sagittal with their free and curved apical actine ( 67-(87.4)-117 um long) protruding into the atrium. The the basal triradiate actines are 33-(59.5)-75 um long, with a maximum thickness of 2-(6.9)-12 um. | | Cortical microdiactines are slender, tapering towards both ends, with a slight thickening about 66% toward their proximal end, and are often finely spined. They are 40-(53.9)-93 um long. |
|
