Pinnularia quesadae Van de Vijver & Zidarova 2011
- Dataset
- Five new taxa in the genus Pinnularia sectio Distantes (Bacillariophyta) from Livingston Island (South Shetland Islands)
- Rank
- SPECIES
- Published in
- Vijver, Bart Van De, Zidarova, Ralitsa (2011): Five new taxa in the genus Pinnularia sectio Distantes (Bacillariophyta) from Livingston Island (South Shetland Islands). Phytotaxa 24: 39-50, DOI: 10.11646/phytotaxa.24.1.6
Classification
- kingdom
- Chromista
- phylum
- Bacillariophyta
- class
- Bacillariophyceae
- order
- Naviculales
- family
- Naviculaceae
- genus
- Pinnularia
- species
- Pinnularia quesadae
description
Valves lanceolate with convex valve margins and rather broadly rounded, non protracted apices. Marginal raised rim surrounding entire valve. Valve dimensions (n = 12): length 24.0 – 35.5 µm, width 8.7 – 9.6 µm. Axial area moderately broad, linear-lanceolate, widening towards central area. Central area small, in some cases almost absent (Fig. 8), rectangular, bordered by 1 – 2 short striae. Raphe lateral with outer raphe branches curved, located on weakly raised rim, clearly visible in LM. Proximal raphe endings unilaterally deflected, pore-like, near pores weakly turned to other side. Distal fissures sickle-shaped. Axial rim connected near apices, marginal rim with raphe fissures continuing on marginal rim (Fig. 56). Transapical striae broad, almost parallel to weakly radiate, nearly equidistant throughout entire valve, 6 – 7 in 10 µm. Striae composed of several rows of small pores, obscured individually by outer covering.
etymology
Etymology: — Named for Prof. Dr. Antonio Quesada (Universidad Autónoma de Madrid), one of the leading scientists in the Byers Peninsula research and one of the principal investigators of the Limnopolar project on this Peninsula. Observations: — Pinnularia quesadae is at present the only member of the Distantes group with a raphe located on an axial raised rim. Based on valve outline and dimensions, P. quesadae may be confused with P. borealis var. pseudolanceolata, but the presence of the rim and the less radiate striation pattern should prevent misidentification (Table 1). Pinnularia perlanceolata has valves that are clearly wider (10.6 – 12.8 µm vs. 8.7 – 9.6 µm) with a more elliptic-lanceolate valve outline, lower number of striae (5 – 6 vs. 6 – 7 in 10 µm in P. quesadae) and an almost straight raphe with straight to weakly deflected central endings.
materials_examined
Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 67, Leg. B. Van de Vijver, coll. date 18 / 01 / 2009, slide no. BR- 4237 (holotype BR), slide PLP- 187 (isotype University of Antwerp, Belgium), slide BRM- 7 / 100 (isotype BRM). Habitat and Distribution: — Pinnularia quesadae is a rare species on Livingston Island and so far only found together with P. perlanceolata and P. borealis var. pseudolanceolata (see above) in a large, circumneutral (pH 7.3) shallow pool on Byers Peninsula surrounded by fellfields and moss vegetations, growing into the water.