Biological Faculty, Moscow State University, Departament of Invertebrate Zoology, Moscow, Russia, 119899

Abstract

Colony growth was studied in hydroid Gonothyraea loveni, a suitable object for investigation of the vital processes regulation in the organism. The colonies were grown up from the separate shoots in the laboratory conditions under the controlled conditions. The daily food supply was changed purposefully during the colony growth. In parallel, the following structural reorganizations were registered: changes in stolon and shoots growth rate, their branching, resorbsion of the hydranths and there repeated formation. Decrease in the daily food supply determines results in rapid (during one day) resorbtion of some hydranths, decreasing of stolon(s growth, ceasing of growth of the oldest shoots. Increase in the daily food supply leads to the reformation (creation) of the hydranths at the places of previously resorbed ones, stolon growth acceleration, stolons and shoots branching. The order of structural reorganization makes visible the organism integrity of the colony: the local processes are spatially differentiated, and as a whole being co-ordinated between one another. Analyses of thr growth regulation mechanisms shows that the effect of the organism integrity is achieved mainly in consequence of the ordered spatial "ruled" differentiation of colony vital functions, but not due to the centralized growth and morphogenetic processes administration.