interspecific hybridization. Niche restriction must have the effect of
facilitating contact between mating partners, although evidence is
circumstantial. The morphological basis of host, site and mate finding
is incompletely known. Thus, although the ultrastructure of sensory
receptors of many species of platyhelminths is known, nothing is known
about their function. Experimental studies are necessary to fill this gap. In
particular, comparative ultrastructural and functional studies of related
alloxenic and synxenic species may yield clues as to the function of
receptors in finding niches and mating partners. Overall, evidence
suggests that the facilitation of mating and segregation to avoid
interspecific hybridization are of very great importance in structuring
communities and determining niche width.Acknowledgements
I wish to thank Sandy Hamdorf for expertly redrawing Figs 9.1 and 9.5,
the editor of the Encyclopedia of Biodiversity and Academic Press
for permission to use Fig. 9.2, the editor of Folia Parasitologicafor
permission to use Figs 9.3 and 9.4, the editor of theInternational Journal
for Parasitologyfor permission to use Figs 9.5 and 9.6 and the editor of
Oikosfor permission to use Figs 9.7 and 9.8.References
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