Gogorev R.M., Davidovich O.I., Davidovich N.A., Bedoshvili Y.D., Nikulin V.Yu., Nikulin A.Yu.
Fottea 2026; 26(2): 140-155
Clonal cultures of the diatom genus Climaconeis from the Black Sea (Crimea), Mediterranean Sea (Anatolia), Atlantic Ocean (Canary Islands), and Southwest Pacific Ocean (Auckland, New Zealand) were investigated. The Auckland population is described as Climaconeis aucklandensis sp. nov., distinguished by 4–12 H-shaped plastids per cell, a larger valve size range, and different stria density. We used morphological (LM, SEM, TEM, LSM), molecular (rbcL), and ecophysiological (salinity tolerance) analyses to characterize C. aucklandensis, C. scalaris, and Climaconeis cf. scalaris. Black Sea and Atlantic specimens resembled C. scalaris but differed diagnostically. New Zealand strains were morphologically close to C. undulata but genetically distinct. Sexual compatibility was confirmed between Black Sea and Mediterranean populations. Three species delimitation methods (ASAP, PTP, GMYC) identified six genetic lineages, supporting significant cryptic diversity within the genus.
