[Relay-ray way of hydroplasm movement in hydroid colonies]

In this study, we continued the investigation of the distribution system of colonial hydroids in the course of its development, starting with its emergence during the planula metamorphosis and ending with the formed colony. The hydroplasmic stream system of two species of colonial hydroids--Perigonimus abyssi G.O. Sars, 1874, and Stauridia producta Wright, 1858--was studied. W found that the main principle by which hydroplasma moves in these colonies, which form no shoots, is the relay-race from one hydranth to another through a stolon fragment connecting them or directly from one hydranth to the next one, etc. W show that the efficiency of the conducting (distribution) system does not depend on the level of complexity of the colonial structure. The results of this study confirm the absence of general colonial processes of integration and self-regulation in hydroid polyps.