Pinnularia subcatenaborealis sp. nov. (Bacillariophyta) a new chain-forming diatom species from King George Island (Maritime Antarctica)

• Published in: Phytotaxa
• Main Authors: KOCHMAN-KĘDZIORA, NATALIA, PINSEEL, EVELINE, RYBAK, MATEUSZ, NOGA, TERESA, OLECH, MARIA, VAN DE VIJVER, BART
• Format: Article in Journal/Newspaper
• Language: English
• Published: Phytotaxa 2018
• Subjects: Algae; new species; Pinnularia; colony formation; freshwater diatoms; Antarctic; Antarctic Peninsula; King George Island; Ross Island; Vega Island; Ecology Glacier; Antarc*; Antarctica; James Ross Island
• Online Access: http://www.mapress.com/j/pt/article/view/phytotaxa.364.3.5; https://doi.org/10.11646/phytotaxa.364.3.5

During a survey conducted on the freshwater diatom flora of small shallow pools on the Ecology Glacier forefield (King George Island, Maritime Antarctic Region), an unknown spine-bearing chain-forming Pinnularia species, belonging to the Pinnularia borealis species complex, was found. Although it closely resembles the recently described Pinnularia catenaborealis from James Ross Island and Vega Island (Antarctic Peninsula), a unique set of morphological characteristics revealed in both light and scanning electron microscopy clearly discriminates the specimens of King George Island as a new species. Pinnularia subcatenaborealis Kochman-Kędziora, Pinseel & Van de Vijver sp. nov. can be distinguished from P. catenaborealis by an overall smaller valve size, the presence of irregularly formed silica outgrowths on the mantle and small, irregular plates located near the apices. The new taxon is so far only recorded from a small pool with circumneutral pH and very low conductivity.