Sara Kabirnataj - Genetic and Agricultural Biotechnology Institute of Tabarestan (GABIT), Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Ghorban A. Nematzadeh - Genetic and Agricultural Biotechnology Institute of Tabarestan (GABIT), Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Ahmad Farhad Talebi - Department of Genetics, Faculty of Microbial Biotechnology, Semnan University, Semnan, Iran
Meisam Tabatabaei - Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII(, Karaj, Iran

The true branched cyanobacteria exhibit multiple shapes, multiple patterns of branching along with displaying interesting types of cells which makes the identification of these forms, interesting but very complex. In this study two strains of true branched heterocystous cyanobacteria, SA33 and SA16, isolated from dried paddy fields of Mazandaran, Iran, were studied using morphological, ecological, and molecular tools. Morphological characterization of the strains indicated them to be commonly showing profuse T-type branching, large irregularly shaped cells of the main filament. Strain SA33 showed the development of interesting biseriate filaments with unilateral branching, while strain SA16 showed uniseriate filaments with bilateral branching. Full-length sequencing of the 16S–23S ITS region and folding of the secondary structures gave interesting secondary structures and comparison with the closely related sequences clearly indicated the secondary structures of both the strains to be unique. All the results indicated the strains to be members of a morphologically cryptic but phylogenetically distinct unknown genus of cyanobacteria. Comprehensive evaluation of all the findings and comparative assessment of previous studies indicate that SA33 and SA16 are indeed two new species of a new genus of true branched cyanobacteria. In accordance with the International Code of Nomenclature, we propose the name of the new genus as Neowestiellopsis with the names of the species being Neowestiellopsis persica and Neowestiellopsis bilateralis

16SrRNA, Cyanobacteria, Neowestiellopsis,True branching cyanobacteria