Morphological description (show/hide)
| Dense mass of anastomosing and branching tubes, with dimensions of 4x 2.5 x 2cm. Tubes have a diameter of up to 5mm, anastomosing in the basal and middle part of the cormus. In the uppermost part tubes branch and end in a terminal osculum. | | white | | white | | A single osculum occurs at each distal end of branched tubes. Osculae diameter up to 5 mm, more-or-less the same diameter as the tubes. | | Firm but easily torn | | Smooth | | With an inarticulated choanoskeleton skeleton, the distal part supported by pseudosagittal triactines, with one paired and the unpaired actine formin the subcortical skeleton, while the longer paired actine together with the unpaired actine of subcortical sagittal triactines support the choanosome. Tangential triactines form the atrial skeleton together with rare tetractines. | | A tangential and irregular layer of sagittal triactines form a thin cortical skeleton. | | Ectosomal triactines are regular, with their conical actines occasionally slightly undulating [109-(142.7)-179_6-(9.4)-14 mm, SD 16.4_1.9 mm]. Subcortical pseudosagittal triactines: longer paired actines [128-(157.7)-197mm long, SD 20.4mm], shorter paired actine [76-(131.9)-169 mm long, SD 22.9 mm], Unpaired actines have a distinct bend in their proximal 25% length, The unpaired actine is 72-(117.1)-176mm long (SD 24.4mm) and 5-(8.6)-12mm thick (SD 2.4 mm). Subatrial sagittal t-shaped triactines (figure 13e) have an unpaired angle of approximately 170¡, with paired angles at about 95¡. Unpaired actines [135-(182)-215 mm long, SD 20.2 mm] are longer than the paired actines [64-(83)-108mm long, SD 9.3mm]. They are conical and pointed with maximum thickness of 4-(8.8)-13mm (SD 2.2mm). Atrial triactines similar to ectosomal traictines, but often with partially bent (slightly curved) paired actines at their proximal end, forming a distinctly ÔcurvedÕ angle. Paired actines have a size of 114-(130.9)-150mm (SD 12.2mm), and unpaired actines 123-(145.8)-166 mm (SD 12.6 mm) (N=10). Rare atrial tetractines are indistinguishable from atrial triactines in the dimensions of the basal triradiate system, but show a very short apical actine. |
|
