The use of echinostomes to study host–parasite relationships between larval trematodes and invertebrate and cold-blooded vertebrate hosts

Abstract

Echinostomes are intestinal trematodes with life cycles that are easy and inexpensive to maintain in the laboratory. For this reason, echinostomes have served for years as experimental models in different areas of parasitology. However, the usefulness of these trematodes in experimental parasitology has been under estimated. In this paper, we discuss the life cycles of echinostomes and the techniques used to maintain them in the laboratory. We further examine the characteristics of these trematodes that make them useful models for the analysis of larval parasite-host relationships. Echinostomes are useful for studies on the immunobiology of snails, host-finding processes of free-living larval stages, effects of larval trematode infections on anuran populations, and studies on analytes in the larval trematodes and their snail intermediate hosts.

Effects of environmental change on helminth infections in amphibians: exploring the emergence of Ribeiroia and Echinostoma infections in North America.

“…While Ribeiroia infection in amphibians has been the subject of extensive field observations and ecological studies (see earlier), species of Echinostoma have proven excellent model organisms for laboratory studies of host-parasite relationships, ranging from physiology to immunology (Huffman and Fried 1990 ;Toledo et al 2007) . Given the ecological similarities of these two parasites in amphibians, we further aim to critically examine evidence for a possible rise in echinostome infection in response to the same drivers that influence Ribeiroia .…”

The role of trematode parasites in larval anuran communities: an aquatic ecologist’s guide to the major players

“…Cercariae of E. trivolvis emerge mostly in the morning hours as emergence rhythm is synchronized by light-dark (Toledo et al 1999(Toledo et al , 2007. In order to obtain cercariae of E. trivolvis, snails within a small dish (a disposable 100 mm Petri dish works well) containing aerated pond water should be placed approximately 30 cm under a 100 W incandescent light bulb (e.g., Koprivnikar et al 2006c;Thiemann and Wassersug 2000).…”

“…E. trivolvis has received much less attention than R. ondatrae, as the signs of infection in amphibians (e.g., edema, growth inhibition or mortality) are easily overlooked or attributed to causes other than echinostome infection. However, Echinostoma infections are important determinants of tadpole survivorship, especially in early developmental stages, and thus can have profound effects on amphibian recruitment rates (Beasley et al 2005;Schotthoefer et al 2003a;Toledo et al 2007).…”

Effects of prolonged worm storage on the viability of Echinostoma caproni eggs

“…Echinostoma caproni is a useful model to study the hostparasite relationships of an echinostomatid in both definitive and intermediate hosts (Toledo and Fried 2005;Toledo et al 2007). This echinostomatid is conveniently cycled in the laboratory between mice and Biomphalaria glabrata (Fried and Huffman 1996).…”