Assessment of the Species Diversity of the Genus Pseudo-nitzschia H. Peragallo, 1900 (Bacillariophyta) in Plankton near Karadag Using Multidimensional Statistical Analysis

More than 50 species are known in the genus Pseudo-nitzschia H. Peragallo, 1900. Seven of them were recorded in the Black Sea. Due to the high morphological similarity, many representatives of the genus are considered to be cryptic; their reliable identification requires the use of different, often very resource-consuming methods. The aim of this study was to estimate the total number of Pseudo-nitzschia species occurring near Karadag (southeastern Crimea) during the period of their mass development in the spring. In addition to expert assessment, we used multivariate statistics methods, which allowed an estimation of the number of species in samples based on simple biometric parameters. Using the initially obtained array of data it was possible to determine the species identity of objects in newly collected samples.