Studies on collar spines of echinostomatid trematodes

This review is mainly concerned with the methods used to study collar spines in echinostomatid trematodes. The salient studies concerned with light microscopy on live and fixed larval and adult echinostomes are reviewed. Similar information is also provided for echinostomatid collar spines examined by scanning electron microscopy and transmission electron miscroscopy. The limited information on specific histochemical studies on these spines is also reviewed. Lastly, an examination of the few papers that have considered structure and function of collar spines is given.