Psammothidium superpapilio Kopalová, Zidarova & Van de Vijver, 2016

Kopalová, Kateřina, Zidarova, Ralitsa & Vijver, Bart Van De, 2016, Four new monoraphid diatom species (Bacillariophyta, Achnanthaceae) from the Maritime Antarctic Region, European Journal of Taxonomy 217, pp. 1-19 : 11-13

publication ID

https://doi.org/ 10.5852/ejt.2016.217

DOI

https://doi.org/10.5281/zenodo.3853082

persistent identifier

https://treatment.plazi.org/id/03873C46-FFC6-FFE5-FEDA-4969A2A2FD5B

treatment provided by

Valdenar

scientific name

Psammothidium superpapilio Kopalová, Zidarova & Van de Vijver
status

sp. nov.

Psammothidium superpapilio Kopalová, Zidarova & Van de Vijver sp. nov.

Figs 86–109 View Figs 86–109

Etymology

The specific epithet refers to the similarity with P. papilio and the larger valve dimensions.

Type

Byers Peninsula, Livingston Island, South Shetland Islands, Antarctica, sample BYM-008 (62°40′11.3″S 61°08′45.3″W) (leg. B. Van de Vijver), coll. date: 9 Jan. 2009 (holo-: slide no. BR–4439; iso-: slide PLP–295, University of Antwerp, Belgium).

Description

Light microscopy ( Figs 86–105 View Figs 86–109 )

Valves lanceolate to lanceolate-elliptic with convex to sometimes more straight margins gradually tapering towards the broad cuneately rounded apices. Valve dimensions (n = 40): length 15–20 µm, width 4.5–5.5 µm. Raphe valve ( Figs 96–105 View Figs 86–109 ): valves clearly convex. Axial area narrow, linear, almost not widening towards the central area. Central area forming a broad rectangular to bow-tieshaped subfascia with several (3–5) shortened striae present near the valve margins. Raphe straight with indistinct, straight proximal endings. Distal fissures not discernible in LM. Transapical striae weakly radiate near the central area, becoming more strongly radiate towards the apices, 28–30 in 10 µm. Areolae not discernible in LM. Rapheless valve ( Figs 86–95 View Figs 86–109 ): thickened marginal crest clearly visible in LM. Axial area very narrow, linear-lanceolate, clearly widening towards the central area. Pseudoraphe clearly present as a series of irregular depressions in the axial area. Central area rounded to rhombical, bordered by several shortened striae. Fascia never present. Transapical striae weakly radiate throughout becoming more strongly radiate towards the apices, 26–29 in 10 µm.

Scanning electron microscopy ( Figs 106–109 View Figs 86–109 )

Raphe valve ( Figs 106–107 View Figs 86–109 ): axial area weakly raised and more heavily silicified ( Fig. 106 View Figs 86–109 ). Striae uniseriate, composed of long series of very small, rounded to rectangular areolae ( Fig. 106 View Figs 86–109 ). Number of areolae per striae diminishing towards the axial area ( Fig. 106 View Figs 86–109 ). On the valve face/margin junction, one transapically elongated areola present. Raphe branches almost straight ( Fig. 106 View Figs 86–109 ). Proximal raphe endings straight, simple, never expanded ( Fig. 106 View Figs 86–109 ). Distal endings short, terminating near the last striae at the apices ( Fig. 106 View Figs 86–109 ). Internally, areolae rectangular, covered by perforated hymenes ( Fig. 107 View Figs 86–109 ). Proximal raphe endings bent into opposite directions. Distal endings terminating onto small helictoglossae ( Fig. 107 View Figs 86–109 ). Rapheless valve ( Figs 108–109 View Figs 86–109 ): Valve clearly concave. Thin, raised marginal crest bordering the entire valve. Axial area with irregular depressions, forming a clear pseudoraphe ( Fig. 108 View Figs 86–109 ). Striae uniseriate composed of small, rounded areolae. Internally areolae covered by individual perforated hymenes ( Fig. 109 View Figs 86–109 ). Virgae not raised.

Ecology and distribution

This new species was up to now only observed with certainty on Livingston Island. The largest population was found living in a terrestrial moss vegetation, at the edge of a shallow lake. The sampling site was clearly influenced by animals with remains of penguins present on the mosses. The sample was dominated by several Psammothidium taxa such as P. germainii (Manguin) Sabbe ( Sabbe et al. 2003), P. aretasii (Manguin) Le Cohu ( Le Cohu 2005) and P. incognitum (Krasske) Van de Vijver & Beyens ( Van de Vijver et al. 2002).

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