Gomphonema Ehrenberg (Bacillariophyceae) from Lower Iguaçu River, Paraná State, Brazil: taxonomy and new records

ABSTRACT This study aimed to inventory the Gomphonema species community from the Lower Iguaçu River, within an area of the Parque Nacional do Iguaçu, Paraná, Brazil, providing descriptions, comments, and photomicrographs of the identified taxa. Monthly collecting was conducted between September 2010 and September 2011 in the plankton of two sampling stations, one downstream from the waterfalls and another upstream. As a result, 21 taxa were identified, including 13 at the species level, three taxonomic varieties, two subspecies, and three at the generic level. Among these, G. alfinitoanum var. alfinitoanum and G. alfinitoanum var. quinquestigmatum are new records for Brazil, while G. lujanense is a pioneering record for the State of Paraná. Expanding knowledge of the geographic distribution of taxa is fundamental for the comprehension of aquatic biodiversity, both locally and nationally, providing reliable support for future research.