Morphological description (show/hide)
| Single tubes, about 1.3 mm in diameter, with an apical osculum, originally only united at their base, now separated . | | yellow | | white | | Each tube with one terminal osculum | | Tetractines of two types (tetractines I with thick apical actines, tetractines II with thin apical actines), their basal actines supporting the tube wall, the apical actines reaching into the atrium (Fig. 4 C-F). Occasional diactines, perpendicular to the sponge wall, are protruding to the outer side (Fig. 4 B). Some smaller perpendicular trichoxea-like diactines can be observed in the sponge wall, but are broken off in the sections and were not detected in the spicule preparations. | | Tetractines I: Basal system equiangular, parasagittal to equiradiate, sometimes all three basal actines differ in length. Basal actines are conical and have sharp tips. Apical actines are thicker at their base than the actines of the basal triradiate system, straight or slightly bent, sometimes hooked. Tetractine I dimensions are: Basal triradiate system: 84 - 179.5 - 291 um x 9 - 13.0 - 19 um (n=20) [unpaired actine of parasagittal tetractines: 199 - 251.1 - 291 um x 9 - 13.5 - 19 um (n=16); paired actines 84.2 - 156.6 - 272 um x 10 - 13.5 - 19 um (n=16)]. Apical actines: 120 - 147.3 - 167 um x 13 - 18.1 - 27 um (n=11); Tetractines II: Basal system equiangular, parasagittal to equiradiate, sometimes all three actines differ in length. Basal actines are conical and have sharp tips. The apical actines are much thinner than the actines of the basal triradiate system and sometimes have a hook-like bent near their tips. Straight apical actines also occur. Tetractine II dimensions are: Basal triradiate system: 68 - 134.2 - 235 um x 5 - 8.7 - 15 um (n=20) [unpaired actine of parasagittal tetractines: 115 - 179.6 - 235 um x 5 - 9.0 - 15 um (n=13); paired actines: 80 - 117.7 - 152 um x 5 - 8.9 - 14 um (n=13)].Apical actines were measured in sections: 35 - 41.8 - 49 um x 3 - 3.5 - 5 um (n=20).Diactines: Straight diactines with two pointed tips, sometimes slightly bent near the end of one tip (Fig. 4 G). Diactine dimensions are: 136 - 207.6 - 274 um x 5 - 6.2 - 8 um (n=10). Smaller, broken trichoxea-like diactines were only observed in sections and were of about the same diameter as the apical actines of tetractines II. |
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Reference (show/hide)
| Voigt, O., Erpenbeck, D., González-Pech, R.A., Al-Aidaroos, A.M., Berumen, M.L. & Wörheide, G. (2017) Calcinea of the Red Sea: providing a DNA barcode inventory with description of four new species. 1–26. |
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