Bibliography of the Monogenetic Trematode Literature of the World, 1758 to 1982

Diseases of amphibians and reptiles

Publisher Summary This chapter presents an overview of raising Xenopus in the laboratory. Xenopus laevis is well suited to the laboratory, perhaps because it survives and proliferates in a variety of nonfastidious conditions in the wild. Many laboratories have raised X. Laevis and the procedures vary greatly, probably reflecting the animal's tolerance. Whenever a few researchers in one area expect to use X. Laevis as a main experimental animal for a period of years, it is worth their making a joint effort to raise them. The chapter also explains the various equipments required for the experiment, such as tanks. Large tanks are used to minimize the equipment needed to change water automatically. Water quality is examined and infectious diseases are also overviewed. Animals captured in South Africa or Southern California contain a number of parasites (for example, nematodes, trematodes, and protozoa), and generally it is advisable not to mix these animals with ones raised in the laboratory, which tend to be parasite free. As general precautions against the spread of diseases, it is recommended that water never be mixed between tanks and that live aquatic food organisms be avoided as they may carry disease organisms.

Raising Xenopus in the laboratory.

Identification and treatment of a lethal nematode (Capillariaxenopodis) infestation in the south african frog, Xenopuslaevis

The introduction of species to multiple continents creates natural experiments suited to the evaluation of ecological hypotheses. For the Enemy Release Hypothesis (ERH), which postulates that the success of invasive populations hinges upon release from the effects of their natural enemies, assessments of parasite loss during invasion across independent geographical replicates are scarce. This study is the first to test the ERH for a globally invasive amphibian, Xenopus laevis, a successful invader on four continents with a well-described parasite fauna. In this study, the metazoan parasite communities of X. laevis from 20 invasive and 27 native sites in five countries and three continents were compared. An overall pattern of reduced parasite diversity in invasive X. laevis was not yet countered by acquisition of novel parasites. Invasive X. laevis harboured impoverished parasite communities that were distinct from those of native X. laevis from undisturbed habitats. Conversely, parasite communities from native X. laevis from disturbed habitats were similar to those from the invasive range. Accompanying parasites were common in the native range and included both generalists with indirect and specialists with direct life cycles. Our findings emphasise that parasite loss is characteristic of the invasion process of X. laevis and possibly contributes to its success as a global invader. The ERH is supported in terms of metazoan parasites as natural enemies, irrespective of the geographical origin, climatic conditions and invasion history of the host populations. This study also draws attention to parasites that co-invade with their hosts as invaders in their own right.

G.E. Cosgrove

Papers

Diseases and parasites of Xenopus, the clawed toad