The study of biorhythms in marine colonial hydroids

Abstract

Biorhythmic activity of the colony of marine hydroids Podocoryne carnea was investigated. Quantitative characteristics were obtained as a result of the analysis of long-term (10 12 h) monitored stolon oscillations. Sliding window Fourier spectrum dynamics as well as the analysis of the system particular trajectories argue that the main feature of hydroid biorhythmic activity is transient chaos. Long-sustained cyclic activity of stolon pieces separated from the colony and the change in stolon oscillation amplitude and frequency after feeding suggest that stolon cyclic behaviour is determined by the network which consists of pacemakers residing in stolon wall cells and the amount and/or state of food particles inside the stolon lumen. The biorhythmic activity of colony from the point of chaos theory is discussed.