Staurosirella manoyloviana Van de Vijver, Jüttner & D. M. Williams, 2024

Van de Vijver, Bart, Kusber, Wolf-Henning, Jüttner, Ingrid, Schuster, Tanja M. & Williams, David M., 2024, Revision of the Staurosirella leptostauron complex (Staurosiraceae, Bacillariophyta) in Europe with the description of three new species, Plant Ecology and Evolution 157 (2), pp. 174-201 : 174-201

Staurosirella manoyloviana Van de Vijver, Jüttner & D. M. Williams sp. nov.

Figs 12 , 13

Type locality.

Willow Creek, Waushara, Wisconsin, USA, Western Lake Michigan Drainage study Unit, 1993 ( ANSP G. C 100049 b).

Holotype.

ANSP G. C 100049 b ( Academy of Natural Sciences , Philadelphia). Figure 12 E illustrates the holotype.

Registration.

http://phycobank.org/103342

Analysed material.

UNITED STATES • Willow Creek, WI; sample ANSP G. C 100049 b, material kept at The Academy of Natural Sciences, Philadelphia, new slide made BR- 4826 ; BR .

LM description.

Frustules rectangular in girdle view, solitary or in pairs, band-like colonies at present not observed. Valves distinctly heteropolar, ovoid in shape throughout the entire cell diminution series. Larger valves slightly more elongated. Headpole not protracted, broadly rounded. Footpole more acutely rounded. Valve dimensions (n = 20): length 15–70 µm, width 8–10 µm. Sternum narrow, linear, very rarely lanceolate. Striae as broad as, or narrower than the virgae, alternating, parallel throughout to weakly radiate towards the apices, 5–6 in 10 µm. Individual areolae clearly discernible in LM. Figure 12 .

SEM description.

Observations based on Morales and Manoylov (2006 b: figs 102–103). Headpole depressed. Marginal spines absent. Striae composed of linear, slit-like areolae, separated by very thin vimines. Areolae only weakly diminishing in length near the sternum. Apical pore fields present on both apices, much larger on the footpole, the latter composed of 5 – 7 long rows of small, rounded pores, entirely situated on the valve mantle. Valvocopula very large, plain. Figure 13 .

Etymology.

The species is named after Prof. Dr Kalina Manoylov ( Georgia College, USA), co-author of Morales and Manoylov (2006 b) discussing several species of Staurosirella .

Associated diatom flora.

The Willow Creek sample is entirely dominated by several species of Staurosirella . Apart from S. manoyloviana , S. ovata and S. moralesii had high relative abundances, with S. manoyloviana being the least abundant. Morales and Manoylov (2006 b) state that Willow Creek in Wisconsin is relatively warm (19.5 ° C) and basic (pH 8.2) and has medium conductivity (348 µS / cm), a nitrate and nitrite concentration of 1.20 mg / L, and an orthophosphate concentration of 0.10 mg / L. Other frequent species in the sample include Amphora indistincta , Cocconeis pediculus , C. pseudothumensis , Geissleria acceptata , several species of Gomphonema , Karayevia clevei , Navicula tripunctata , and Psammothidium lauenburgianum . Most of these species are characteristic for alkaline waterbodies with higher trophic levels (meso-eutrophic) ( Lange-Bertalot et al. 2017).

Figures

Figure 12. Staurosirella manoyloviana Van de Vijver, Jüttner & D. M. Williams sp. nov., LM micrographs taken from the type material (ANSP G. C 100049 b, Willow Creek, United States). A – B. LM pictures of two frustules in girdle view. C – T. LM pictures of valves in valve face view in decreasing length. Note the change in valve outline in the smaller valves. Scale bar = 10 µm.

Figure 13. Staurosirella manoyloviana Van de Vijver, Jüttner & D. M. Williams sp. nov., SEM micrographs taken from the type material (ANSP G. C 100049 b, Willow Creek, United States). A. SEM view of a frustule in girdle view. B. SEM view of the valvocopula with the fimbriate extensions. C – D. SEM external view of two complete valves. E. SEM internal view of a complete valve. Scale bar = 10 µm (C – E), 5 µm (A – B).