HETEROGENEOUS PIGMENT COMPOSITION OF PHYCOERYTHRIN-CONTAINING PICOCYANOBACTERIA SYNECHOCOCCUS SPP IN THE BLACK-SEA

Natural picoplankton communities in the Black Sea involve phycoerythri n-containing cyanobacteria of two spectral types, which differ in the position of phycoerythrin (PE) fluorescence maximum. Type 1 exhibits a maximum at 558-569 nm, while type 2, at 570-579 nm. The abundance and distribution of various spectral groups of Synechococcus spp, in the Black Sea differ from those in the ocean, although, in both cases, ''s horter-wavelength'' forms dominate in deep waters. Namely, cyanobacter ia containing PEs of the WH8103 type (with a superhigh content of phyc ourobilin) dominate in the open ocean, while those of type 1 (the rela tive content of phycourobilin is unknown) are prevalent in the open Bl ack Sea. At the same time, dominant cyanobacteria living in the coasta l waters are of the WH7803 type (the ocean) and type 2 (the Black Sea) . The intensity of cell fluorescence changes with depth.