Luticola transantarctica

Taxon ID: 389
Author: Kohler & Kopalová 2015   
Basionym:
Synonym:

 

Images

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LM image scalebar = 10 µm = 72 pixels      SEM image scalebar = 10 µm  

 

Observations

Observations: Tyler Kohler and Katerina Kopalová
Length: 16.0–50.9 µm
Width: 7.1–10.6 µm
Striae: 18–22 in 10 µm

Description:

Valves elliptic-lanceolate becoming slightly rhombic in larger specimens. Apices broadly rounded, in smaller specimens slightly rostrate. Margins symmetrical, convex and rounded in central area. Valve dimensions: length 16.0–50.9 ?m, width 7.1–10.6 ?m. Axial area narrow, expanding slightly towards central area. Central area rectangular to elliptical, bordered by 1–2 areolae on both sides. Rounded isolated pore in central area located half way between valve center and valve margin. Raphe branches straight with both proximal and distal endings slightly deflecting away from isolated pore. Striae radiate throughout entire valve, 18–22 in 10 ?m (n=25).

Morphology:
Distribution: South Victorialand endemic

Autecology:

 

Notes:

If observed at all, the lower size range of this taxon may have previously been identified as L. muticopsis f. reducta (W. & G.S. West) Spaulding because of images published by Kellogg et al. (1980), which appear to show the reduced form of L. gaussii or other Luticola with rounded apices. Like N. muticopsis f. evoluta, there is no original illustration for L. muticopsis f. reducta, and the description is limited to “Cells are shorter, poles less drawn out and distinctly truncated, striae 13 in 10 ?” (translated from Latin, West & West 1911: 284). However, since L. transantarctica was not was not observed in our survey of Cape Royds nor in the original West & West slides, we conjecture that the two are not conspecific. Based on published images, it is also possible that L. transantarctica has been observed in the past and identified as L. murrayi (Kellogg et al. 1980: 176, pl. 1, Fig.20) or Naviula globiceps f. amphicephala (Ko-Bayashi 1963: 13, pl. 4, Fig.3), but these populations should be re-investigated before this could be said for certain. From the Antarctic continent, Luticola transantarctica is most similar in morphology to L. pseudomurrayi, described from Langhovde, Lützow Holm Bay, East-Antarctica (Van de Vijver et al. 2012). However, L. transantarctica differs from L. pseudomurrayi by having more capitate apices, with narrower constrictions between the apices and the valve center. Lastly, L. pseudomurrayi has a larger upper width range than L. transantarctica (7.5–12.0 ?m vs 7.1– 10.6?m). From the McMurdo Sound Region, L. transantarctica could be confused with L. elegans, especially at the lower end of the size range. However, apices in L. transantarctica remain capitate at small sizes, whereas in L. elegans they become more rostrate at lower as well as greater sizes. Luticola gaussii is very similar in valve outline, especially at intermediate lengths. However, L. gaussii has a more rounded central area compared 1030 to the elliptic central area in L. transantarctica, and L. gaussii additionally has slitted punta under SEM. Furthermore, the striae of L. gaussii are patterned as noted by West & West (1911), with two lines running along the axial area in the valve center and one at the apices. In L. transantarctica, striae form no such pattern, are punctate and irregular. Finally, L. gaussii is consistently wider than L. transantarctica at any given length. If observed at all, the lower size range of this taxon may have previously been identified as L. muticopsis f. reducta (W. & G.S. West) Spaulding because of images published by Kellogg et al. (1980), which appear to show the reduced form of L. gaussii or other Luticola with rounded apices. Like N. muticopsis f. evoluta, there is no original illustration for L. muticopsis f. reducta, and the description is limited to “Cells are shorter, poles less drawn out and distinctly truncated, striae 13 in 10 ?” (translated from Latin, West & West 1911: 284). However, since L. transantarctica was not was not observed in our survey of Cape Royds nor in the original West & West slides, we conjecture that the two are not conspecific. Based on published images, it is also possible that L. transantarctica has been observed in the past and identified as L. murrayi (Kellogg et al. 1980: 176, pl. 1, Fig.20) or Naviula globiceps f. amphicephala (Ko-Bayashi 1963: 13, pl. 4, Fig.3), but these populations should be re-investigated before this could be said for certain. From the Antarctic continent, Luticola transantarctica is most similar in morphology to L. pseudomurrayi, described from Langhovde, Lützow Holm Bay, East-Antarctica (Van de Vijver et al. 2012). However, L. transantarctica differs from L. pseudomurrayi by having more capitate apices, with narrower constrictions between the apices and the valve center. Lastly, L. pseudomurrayi has a larger upper width range than L. transantarctica (7.5–12.0 ?m vs 7.1– 10.6?m). From the McMurdo Sound Region, L. transantarctica could be confused with L. elegans, especially at the lower end of the size range. However, apices in L. transantarctica remain capitate at small sizes, whereas in L. elegans they become more rostrate at lower as well as greater sizes. Luticola gaussii is very similar in valve outline, especially at intermediate lengths. However, L. gaussii has a more rounded central area compared 1030 to the elliptic central area in L. transantarctica, and L. gaussii additionally has slitted punta under SEM. Furthermore, the striae of L. gaussii are patterned as noted by West & West (1911), with two lines running along the axial area in the valve center and one at the apices. In L. transantarctica, striae form no such pattern, are punctate and irregular. Finally, L. gaussii is consistently wider than L. transantarctica at any given length.

 

McMurdo Dry Valleys Waterbodies with Luticola transantarctica

  • Bowles Creek
  • Canada Stream
  • Delta Stream
  • Huey Creek
  • Lost Seal Stream
  • Von Guerard Stream

Original Type Description

Author: Kohler & Kopalová 2015
Length: 16.0–50.9 µm
Width: 7.1–10.6 µm
Striae: 18–22 in 10 µm

Original Description:

 

New combination

Author:

 

Citations

Index Nominum Algarum (INA):

  • 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).

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