Abstract
The axial organ of two sea urchin genera, Echinometra and Eucidaris, has been analysed with the electron microscope. It is mainly built up by an extracoelomic tissue rich in various leucocytic cells and blood vessels lacking an endothelium. The axial sinus (axocoel) is located on the interior of the axial organ, and evaginations extend into this loosely constructed tissue. The epithelium of the axial sinus and its extensions are characterized by epitheliomuscular cells and abundant podocytes, which overlie the blood vessels. Since podocytes are the well known structural basis for ultrafiltration, it is postulated that this is a function of the axial organ at least in echinoids and asteroids.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
