Understanding the Biodiversity, Ecology and Evolution of Parasites: Central Problems and How to Solve Them

Important problems related to estimating species numbers of parasites, as well as ecological/evolutionary aspects of parasite biology are discussed. Particular attention is paid to some methods commonly used in parasite ecology, ie., the demonstration of an asymptotic relationship between infra- and component community richness to show species saturation, the use of percent similarity indices, and the distinction of 'specialist' and 'generalist' parasite species. The usefulness of an 'holistic' approach using several methods is emphasized. Metazoan parasites (and especially ectoparasites) of marine fishes have been most thoroughly examined with regard to the question of whether equilibrium or non-equilibrium conditions prevail, and the various methods used in these studies are listed. Only one study has dealt with the problem of allo- vs. synxenic speciation in parasites using methods of molecular biology, few studies deal with metapopulation biology in parasites, and none with chaos. Attention is drawn to a new method, that of fuzzy chaos modelling, and the suitability of parasites to test predictions of fuzzy chaos. The need to examine the function of the great variety of sensorreceptors shown to occur in various parasites, as well as the necessity to study various other aspects of functional morphology/ecology are stressed.