First record of Gomphonema lacunicola Patrick et Freese (Bacillariophyta) from the Pâreng Mts (Southern Carpathians, Romania)

Here we report and document the occurrence of the diatom Gomphonema lacunicola Patrick et Freese 1961 from the Pâreng Mts of the Carpathian Mountains, Romania. This observation was made within the framework of a systematic sampling campaign and analyses that were conducted in the Southern Carpathians, covering 40 mountain lakes for discovering the cladoceran fauna and diatom flora of this region between 2012 and 2014. G. lacunicola was found only in one of the 40 lakes, namely in Lake Câlcescu, where it was extremely rare, but the characteristic feature of the lake promoted the presence of the species. Lake Câlcescu is a subalpine lake, located 1,934 m a.s.l. This is the first record of this diatom species in Romania.