The development and function of the heart and pericardium in echinodermata

Publisher Website
Google Scholar
Abstract
Studies were on Echinus miliaris and Asterias rubens. The pericardial vesicle arises as a solid bud from the posterior part of the right anterior coelom. It becomes hollowed out and extends dorsally. Pulsations occur in the floor of the vesicle and travel forwards. The heart of E. miliaris beats about 4 times as much as that of A. rubens. The fluid contained in the heart is the blastocoelic fluid with the rich juice exuded by the stomach cells. Mg chloride in small concentrations decreases the number of beats per min. KCl in small quantities increases the contraction rate. In late plutei the floor becomes permanently invaginated in the vesicle forming the heart. In late brachiolariae the spongy tissue underneath invades the invaginated floor of the vesicle. The vesicle persists in the adult star-fish and sea-urchin, lying on the dorsal side directly under the madreporite as a closed sac. The pericardial vesicle of echinoderms is homologous with the pericardial vesicle of Balanoglossus.

This publication has 2 references indexed in Scilit: