ABSTRACT
Numerous components of the water-vascular and peripheral nervous systems are embedded among the skeletal ossicles of the starfish ambulacrum. New insights into the operation and coordination of the tube feet and ampullae might be gained through exploration of the relationships of these systems, so we have adopted standard preparative techniques and adapted others to decalcify the skeletal ossicles without detriment to the morphology and relationships of the soft tissues. Large, glutaraldehyde-stabilized segments of the ambulacrum, measuring 10–15 mm in length, have been decalcified with ascorbic acid (vitamin C). These segments, if infiltrated and embedded in a glycol methacrylate-based plastic, yield thin histological sections with excellent cytological detail. Despite the protracted periods of fixation, decalcification, and dehydration, the ambulacral segments, following exposure to a buffered osmium tetroxide, can be infiltrated and embedded in an epoxy resin for correlative light and transmission electron microscopy. The decalcified specimens are also suitable, when dried by the critical-point method, for examination with the scanning electron microscope.
