Seasonal dynamics and ecological drivers of Prorocentrum micans Ehrenberg dinoflagellate blooms in Qarun Lake, Egypt

Abstract

The morphological description of the dinoflagellate Prorocentrum micans, based on light and SEM microscopy, population dynamics, environmental drivers and seasonal abundance fluctuations were recorded in Qarun Lake during different seasons during the period from 2018 to 2019. The highest bloom of P. micans was observed in summer and autumn, but it declined in winter. This blooming was highly correlated to the increased water salinity and temperature. The seasonal cellular changes included partial deterioration of the cytoplasmic organelles that was observed in autumn, and many ruptured individuals with chlorophyll leakage in winter. As for the cellular proteins, many polypeptides were significantly down-regulated downstream from summer to winter. Induction of protein phosphorylation steady state was found in winter samples. This most likely contributed to signal transduction cascades regulating programmed cell death and abundance of the fluctuations of P. micans during seasonal changes. The proteomic study provided insights into the population dynamics and the ecological drivers of P. micans.