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Observations
| Observations: | Bart Van de Vijver |
|---|---|
| Length: | 25-52 µm |
| Width: | 8-12 µm |
| Striae: | Central: 16-17, Distal: 24-25 in 10 µm |
Description:
Valves linear-lanceolate, broadly lanceolate to even rhombic lanceolate with clearly convex margins and broadly rounded to slightly protracted valve ends. Valve face/mantle margin forming a broadly rounded edge followed by a rather narrow mantle. Valve length 25-52 µm, valve width 8-12 µm. Axial area moderately broad and linear, widening only very slightly to form an elliptical central area with a clear rectelevatum. Towards the apices, axial area becoming wider. Raphe filiform with the proximal raphe endings clearly separated, short and unilaterally bent, never passing the first row of areolae. External distal raphe deflected to the same valve side as the proximal endings, never divergent at his terminus. Terminal fissures remaining entirely on the valve face, never extending onto the mantle (. Striae bordering the central area (5-7 striae) more spaced than the other striae and clearly radiate whereas the other striae, more distant from the central area, only moderately to slightly radiate, central striae 16-17 in 10 µm, distal striae 24-25 in 10 µm. Near the valve ends, striae becoming even parallel. Striae composed of small, rounded to weakly transapically elongated areolae, similar in size and shape throughout the entire valve. First row of areolae bordering the axial area with slightly larger areolae and clearly separated from the other rows by a narrow hyaline area. Near the distal raphe ends, presence of canal puncta not obvious although in some specimens they are clearly present. Internally, areolae occluded by vela. Centrally, the longitudinal canal broad and becoming rib-like distally terminating at the helictoglossa. No perforations to the longitudinal canal observed.
| Morphology: | Naviculoid |
|---|---|
| Distribution: |
Autecology:
Notes:
The non-divergent terminal raphe endings of M. sabbei are found in five other Muelleria species. Muelleria rostrata can be unequivocally distinguished by its completely different valve outline with typical capitate ends. Muelleria variolata, described from Signy Island (South Orkney Islands), has an irregular valve surface with an external longitudinal depression bordering the axial area and a different valve shape. M. kristinae has a different striation pattern lacking any difference in stria density between the striae near the central area and the other striae, while M. australoatlantica possesses two types of areolae. The last species to compare with, M. meridionalis, has so far only been found on the Antarctic Continent. M. meridionalis differs in valve outline (clearly gibbous in the middle) with undulating margins and a slightly narrower valve width (max. 10 µm versus 8-12 µm in M. sabbei). All other species have divergent terminal raphe endings. Based on valve outline, M. sabbei bears a large resemblance to M. linearis and M. gibbula. Both species however, have a divergent terminal raphe ending. M. gibbula lacks the hyaline line separating the first row of areolae from the other species, clearly present in M. sabbei. M. linearis has long central raphe endings, clearly extending into the first and even second row of areolae, a feature not observed in M. sabbei. Muelleria regigeorgiensis, often present in the same samples as M. sabbei can be separated by its coarser striae, with a geniculate crack close to the axial area whereas the striae in M. sabbei are always much finer lacking the typical geniculate structure. Moreover, in SEM, it is clear that M. regigeorgiensis has bifurcating terminal raphe ends.
Other sites with Muelleria sabbei
- Pools (moist habitats), King George Island
Original Type Description
| Author: | Van de Vijver & Spaulding 2009 |
|---|---|
| Length: | 25-52 µm |
| Width: | 8-12 µm |
| Striae: | Central: 16-17, Distal: 24-25 in 10 µm |
Original Description:
Valvae lineares-lanceolatae, late lanceolatae ad paene rhombico lanceolatas marginibus distincte convexis apicibusque late rotundatis ad etiam leviter protractis. Longitudo 25-52 µm, latitudo 8-12 µm. Area axialis moderate lata, linearis, dilatans ad aream centralem ellipticam. Rectelevatum claro adest. Raphe filiformis, recta terminationibus proximalibus brevibus unilateraliter flexis, numquam extensis in primam seriem areolarum. Terminationes distales numquam divergentes, fissurisque semper in faciei valvae. Striae centrales (5-7 striae) distantiores, manifeste radiatiores. Striae distantes leviter ad moderate radiatae, parallelae ad polos. Striae, 16-17 in 10 µm ad centrum, 24-25 in 10 µm ad polos. Amplitudo areolarum omnino uniformis. Series prima areolarum leviter expansa, separata aliis seriebus ab area hyalina. Puncta canalis non semper adsunt.
New combination
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Citations
Index Nominum Algarum (INA):
- Original
- New Combination
- If an INA link is available, it will be shown above
- The INA is a bibliographic reference "card file" for algal taxonomy, containing nearly 200,000 names of algae (in the broad sense).
