Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 2546

G. Uhlig and G. Sahling; Rhythms and Distributional Phenomena in Noctiluca miliaris. Annales de L'Institut Oceanographique 58:277-284, 1982

Reprint

In File

Notes

Since 1963 Noctiluca miliaris has been cultivated in the Helgoland laboratory. Additional results of long term field studies are based on more than 14 years continuous monitoring of the seasonal and annual distribution near Helgoland. As proved by comparative lab and field studies, cell division of Noctiluca follows a circadian rhythm with a maximum reproduction activity during the night. The outburst of the seasonal Noctiluca-bloom varies between April and June. Independently of this variation, an abrupt disintegration occurs every year precisely during the first ten days of August. The peaks of maximum abundance always fall within the first ten days of July, an exactly 6 months later in January low but distinct winterpeaks are apparent. It is suggested that growth of Noctiluca in the field follows a seasonal circ-annual rhythm. The distribution of Noctiluca in the German Bight has been studied during several summer cruises covering monthly an extended station sampling grid. Highest abundance were found off the East- and North-Frisian islands with a strong gradient towards the inner region of the German Bight. Consequently, Noctiluca shows a tidal oscillation pattern, depending on the locality of actual sampling.