The role of pyrophyta branch in the aquatic environment of the Southern basin of the Caspian Sea

Ongoing changes in microscopic plants including Pyrophyta can have effect on fish migration patterns, their growth rate, mortality rate, and of course the critical gas concentrations in the atmosphere. This study was conducted in the spring, summer, autumn and winter, at ۴۰ study sites from ۸ transect between Astara to the border of Hasangholipour of the Southern Caspian Sea in Iran. A total of ۲۴ species were identified from the phylum Pyrophyta. Most species diversity Pyrophyta in winter (۱۷ species) has been that species Peridinium achromaticum, Peridinium latum, Exuviaella cordata, Prorocentrum praximum, Prorocentrum scutllum and Goniaulax polyedra, were observed in all seasons. Pyrophyta with an average density of ۲۸.۱۷±۲۷.۱۴ (n.m-۳×۱۰۶) and the average biomass annually ۳۴۹±۳۳۶ (mg.m-۳) of approximately ۹% density and ۴% biomass phytoplankton of area in the country. The diversity, density and biomass of Pyrophyta have significant changes and the maximum density Pyrophyta ۲۸.۱۷±۲۷.۱۴ (n.m۳×۱۰۶) and maximum biomass ۳۳۴۹ ±۳۳۶ mg.m-۳, respectively.

Keywords:

Phytoplankton , Pyrophyta , Species , aquatic environment , Caspian Sea