Eunotia mobileensis sp. nov. (Bacillariophyceae) and other elongate Eunotia described from Alabama, USA

The acidophilic genus, Eunotia Ehrenb., often dominates the diatom flora of habitats with soft waters low in pH and conductivity. Exploration of such environments around the globe continue to reveal new species and expand morphological and ecological information of the genus. Collections from the north end of Big Creek Lake, an artificial reservoir that serves as part of the water supply for the city of Mobile in Mobile County, Alabama, USA, revealed a particularly-rich eunotioid flora. A new Eunotia species is described from Big Creek Lake, Eunotia mobileensis sp. nov. The newly described taxon has elongate, narrow, straight valves with spatulate apices and rounded ends. Frustules are joined in colonies in branching arrangements. Each valve apex contains a prominent tooth-like rimoportula on opposite ends of the frustule. The branched-chain growth form, where cells attach end to end and regularly branch out, further separate this taxon from most other Eunotia taxa. This taxon is compared to other Eunotia species with similar growth form and morphology. The diversity of eunotioid diatoms observed in this habitat remains under exploration.