A tropical pseudocryptic cyanobacterium Nectelia purpurascens gen. et sp. nov. (Cyanobacteriophyta, Nodosilineales) from a mangrove habitat in the Gulf of Thailand

SUMMARY

Thin, filamentous and homocytous cyanobacteria continue to pose taxonomic challenges due to their simple morphology and high cryptic diversity. At the same time, tropical regions are important but still underexplored hotspots for new cyanobacterial taxa. In this study, we investigated a Gibliniella ‐like morphotype isolated from a mangrove environment in the Gulf of Thailand. Despite minor morphological differences, both 16S rRNA gene and 16S–23S rRNA internal transcribed spacer (ITS) phylogenies indicated that the studied strain clustered with “ Gibliniella ” gelatinosa in a robustly supported clade that was phylogenetically distant from Gibliniella alaskaensis . Based on these findings together with habitat preference, we propose Nectelia purpurascens gen. et sp. nov. to accommodate the studied strain. Additionally, we proposed the reclassification of “ Gibliniella ” gelatinosa as Nectelia gelatinosa comb. nov., following the provisions of the International Code of Nomenclature for algae, fungi, and plants (ICN). Our findings highlight the underestimated diversity of tropical mangrove cyanobacteria and the polyphasic approach as an effective tool for resolving morphologically depauperate taxa.