Seasonal distribution, abundance, and external morphological changes of Ceratium hirundinella in the Kralkızı and Dicle dam reservoirs on the Tigris River were investigated during 1 year (February 2008 to January 2009). This species was present in both dam reservoirs during all 4 seasons. | Turkish Journal of Botany Turk J Bot (2016) 40: 112-119 © TÜBİTAK doi: Research Article External morphological variations and temporal distribution of the dinoflagellate Ceratium hirundinella in two dam reservoirs in the Tigris River basin (Turkey) Memet VAROL* Department of Basic Aquatic Sciences, Faculty of Fisheries, İnönü University, Malatya, Turkey Received: Accepted/Published Online: Final Version: Abstract: Seasonal distribution, abundance, and external morphological changes of Ceratium hirundinella in the Kralkızı and Dicle dam reservoirs on the Tigris River were investigated during 1 year (February 2008 to January 2009). This species was present in both dam reservoirs during all 4 seasons. The highest mean density of C. hirundinella in Kralkızı Dam Reservoir was recorded in December, while in Dicle Dam Reservoir it was highest in June. C. hirundinella cells had a fourth horn in both dam reservoirs during the study period, and morphologically they showed the highest relative standard deviation in the fourth horn. In addition, a new fifth horn occurred on some cells, always between the antapical and postequatorial horns. Total length, length of antapical horn, and length of the fourth horn of C. hirundinella displayed significant seasonal variations (P ). Water quality parameters did not show significant correlation with C. hirundinella density in the KDR. Cysts of C. hirundinella were not observed in the KDR during the study period. C. hirundinella was present in all seasons during the study period in the DDR. Although the mean numbers of cells were higher in summer and autumn, there were no statistically significant differences among the seasons (ANOVA, P > ). The cells of C. hirundinella remained Table 1. Mean, minimum, and maximum values of water quality parameters in Kralkızı and Dicle dam reservoirs. Kralkızı Dam Reservoir Dicle Dam .
