Pinnularia australomicrostauron Zidarova & Kopalová & Vijver 2012, sp. nov.

• Main Authors: Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De
• Format: Other/Unknown Material
• Language: unknown
• Published: 2012
• Subjects: Biodiversity; Taxonomy; Chromista; Bacillariophyta; Bacillariophyceae; Naviculales; Naviculaceae; Pinnularia; Pinnularia australomicrostauron; Byers; Byers peninsula; Livingston Island; Sickle; South Shetland Islands
• Online Access: https://zenodo.org/record/4929569; https://doi.org/10.5281/zenodo.4929569

Pinnularia australomicrostauron sp. nov. (Figs 135–159) Valvae lineares in speciminibus maioribus ad lineares-ellipticae in speciminibus minoribus marginibus parallellae ad moderate convexis. Specimina marginibus leviter undulates. Apices late subrostrati-subcapitati, leviter protracti ad late rotundati in specimibus minoribus. Longitudo 30–93 µm, latitudo 8.4–14.6 µm. Area axialis distincte lanceolata, angusta in apicibus, dilatans in aream centralem. Area centralis formans fasciam rhombicam, plerumque asymmetricam in speciminibus majoribus, latam. Striae centrales nonnullae abbreviatae in area centrali speciminum maiorum. Raphe lateralis terminationibus raphis proximalibus deflexis cum poris magnis guttiformibus. Fissurae raphis distales falcatae. Striae leviter ad moderate radiatae in media parte valvae, parallelae ad moderate convergentes ad apices, 12–15, pro parte maxima 13–14 in 10 µm. Lineae speciosae longitudinales nullae. Valves linear in larger specimens to linear-elliptic in smaller specimens with parallel to moderately convex margins. Larger valves with weakly undulated margins. Valve apices broadly subrostrate-subcapitate, weakly protracted to broadly rounded in smaller ones. Valve dimensions (n=45): length 30–93 µm, width 8.4–14.6 µm. Axial area distinctly lanceolate, narrow near the apices and widening towards the central area. Central area forming a large rhombic, usually asymmetrical, fascia in larger specimens. Smaller specimens only with rhombic to rounded central area with shortened striae bordering the area. Raphe lateral with deflected proximal raphe endings terminating in droplike large pores. Distal raphe fissures sickle-shaped. Striae weakly to moderately radiate in the middle, almost parallel to moderately convergent towards the apices, 12–15, mostly 13–14, in 10 µm. Longitudinal lines absent. Type:— Byers Peninsula, Livingston Island, South Shetland Islands, sample BY061, leg. B. Van de Vijver, coll. date 17/01/2009, slide no. BR-4256 (holotype BR), slide PLP-201 (isotype University ...