The genus Gomphonema (Bacillariophyta) in Rara Lake, Nepal: taxonomy, morphology, habitat distribution and description of five new species, and a new record for Gomphoneis qii

Abstract

During the first study of the diverse diatom assemblages in Rara Lake, the largest lake in Nepal, 11 species of Gomphonema, belonging to six morphological groups, and Gomphoneis qii could be investigated using light and scanning electron microscopy. Five new Gomphonema species are described: Gomphonema subodhii, Gomphonema parasundaense, Gomphonema raraense, Gomphonema parapygmaeum and Gomphonema himalayaense. Known species included Gomphonema sublaticollum, Gomphonema cf. capitatum, Gomphonema minusculum, Gomphonema lateripunctatum, Gomphonema tergestinum (the only one previously recorded from Nepal) and Gomphonema vibrio. The history of the latter name is explained in detail. The distribution of the Gomphonema species, number of species and records in the littoral of the lake shore varied and was related to the presence of suitable substrata, land use and season, with more records and species present in spring than in autumn.This publication is dedicated to the victims of the earthquakes which hit Nepal in 2015 and to their families.