Fallacia californica sp. nov. (Bacillariophyta), a new freshwater diatom species from streams in California, USA

Abstract

Small naviculoid diatoms remain largely taxonomically unexplored in the United States, due to the inability for clear differentiation of unique characteristics under light microscope magnification during routine identification. In a recent study of benthic stream diatoms from California and as a part of taxonomy data quality assurance and quality control process it became evident that taxonomic reevaluation of a common Fallacia species is needed. A new small-celled Fallacia species is described here and compared to similar taxa. Nomenclatural and ecological discussions, based on historical and current literature, are presented for each taxon. Type materials were consulted for taxonomic evaluation and comparison. The new taxon is described with light microscopy and scanning electron microscopy. Fallacia californica could be distinguished from other small Fallacia species with coarse areolae by the unique combination of following features: 1) distinct lyre-shaped sternum, 2) asymmetrical central area, and 3) variable central striae with one to four inner areolae absent, and unilateral gap between the central striae on the mantle. The new freshwater species was distributed in warm alkaline waters with medium conductivity and elevated nutrients content.The majority of populations have been recorded in coastal streams, where they could be abundant, but the species could be scattered in other inland running waters as well.

Morphology, molecular phylogeny and systematics of the diatom genus Fallacia (Sellaphoraceae), with descriptions of three new species1

“…1999, Garcia 2003, Li et al. 2014a, 2015, 2019, Stancheva and Manoylov 2018). Currently, the genus Fallacia contains over 100 species (Kociolek et al.…”

“…Bacillares (Hustedt 1961(Hustedt -1966. Since the establishment of this genus, 46 new species and combinations have been described from all over the world (Witkowski 1991, Ake-Castillo et al 1999, Sabbe et al 1999, Garcia 2003, Li et al 2014a, 2019, Stancheva and Manoylov 2018. Currently, the genus Fallacia contains over 100 species (Kociolek et al 2021).…”

Planothidium sheathii, a new monoraphid diatom species from rivers in California, USA

“…In the last decade, the extensive stream bioassessment sampling of the California Water Resource Control Board Surface Water Ambient Monitoring Program (SWAMP) provided data for a description of new-to-science species belonging to the diatom genera Amphora Ehrenberg ex Kützing (1844: 107), Halamphora (Cleve) Levkov (2009: 165) (Stepanek & Kociolek 2013), Rhoicosphenia Grunow (1860: 511) (Thomas & Kociolek 2015), Gomphonema Ehrenbrg (1832: 87), Gomphoneis Cleve (1894: 73) (Stancheva et al 2016), Fallacia Stickle & D.G. Mann (1990 (Stancheva & Manoylov 2018), Cocconeis Ehrenberg (1836: 173) (Stancheva in press) and to the green algal genera Zygnema C.A. Agardh (1817: 98) (Stancheva et al 2012), Spirogyra Link (in Nees 1820: 5) (Stancheva et al 2013), and Ochlochaete Thwaites (1849: Pl.…”

First record of the rare freshwater alga Tetrasporopsis fuscescens (Chrysomerophyceae, Ochrophyta) in North America

“…Agardh , Spirogyra Link (Stancheva et al 2013), Ochlochaete Thwaites (Hall et al 2018) and diatoms Amphora Ehr. ex Kütz., Halamphora (Cleve) Levkov (Stepanek & Kociolek 2013), Rhoicosphenia Grunow (Thomas & Kociolek 2015), Gomphonema Grunow, Gomphoneis Cleve , Fallacia Stickle et D. G. Mann (Stancheva & Manoylov 2018), Cocconies Ehr., Planothidium Round et Bukhtiyarova (Stancheva 2019 a, b), as well as the first record of the freshwater brown alga Pleurocladia lacustris A. Braun (Wehr et al 2013).…”