Phylogenetic analysis of European species of Proteocephalus (Cestoda : Proteocephalidea): compatibility of molecular and morphological data, and parasite-host coevolution

The phylogeny of European species of the tapeworm genus Proteocephalus was studied, based on partial 18S rDNA and morphological data. The group was fo und to be monophyletic. The analysis showed a low informative value of avai lable morphological characters in comparison with molecular data. The morph ological matrix resulted in a poorly resolved tree which is, however, compa tible with the topology (Proteocephalus osculatus (Proteocephalus torulosus (Proteocephalus macrocephalus, Proteocephalus filicollis) (Proteocephalus tetrastomus, Proteocephalus percae, Proteocephalus longicollis))) based on the 18S rDNA data. A comparison performed by the program TreeMap showed a l ack of significant congruency between parasite and host phylogenies. Theref ore, the distribution of species in their hosts appears to be independent o f the phylogeny and it is likely to be a result of host-switching, rather t han co-speciation events. (C) 2001 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.