Insight into the morphology and genetic diversity of the <i>Chaetoceros tenuissimus</i> (Bacillariophyta) species complex

Among the marine planktonic diatoms, Chaetoceros is among most species-rich genera, and many species are considered important primary producers. However, little known about ecology distribution of few small solitary within this genus, including tenuissimus. This article describes a minute strain, identified as C. tenuissimus (named CT16ED) that was isolated at coastal lagoon in Corsica Island, Western Mediterranean. The strain characterized by light microscopy scanning transmission electron microscopy, with specific focus on fine structure construction setae its behaviour culture. CT16ED compared other strains we from type locality (Ostend Harbour, North Sea) sequencing fragment nuclear ribosomal DNA (rDNA) spanning 18S rDNA to D3 region 28S rDNA, plastid rbcL gene codes large RuBisCO subunit. Based literature available sequence data, analysed were similar but phylogenetic analysis indicated complex contained several clades, therefore current taxonomic status discussed. comparison data assigned synonyms tenuissimus, simplex var. calcitrans, calcitrans f. pumilus, suggested these taxa paraphyletic genus Chaetoceros.