Cryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasite.

TitleCryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasite.
Publication TypeJournal Article
Year of Publication2007
AuthorsSteinauer ML, Nickol BB, Ortí G
JournalMolecular ecology
Volume16
Issue19
Pagination4097-109
Date Published2007 Oct
ISSN0962-1083
KeywordsAcanthocephala, Animals, Bayes Theorem, Fishes, Genetic Speciation, Haplotypes, Host-Parasite Interactions, Likelihood Functions, Phenotype, Phylogeny, Sequence Alignment, Species Specificity
Abstract

An investigation of a parasite species that is broadly host- and habitat-specific and exhibits alternative transmission strategies was undertaken to examine intraspecific variability and if it can be attributed to cryptic speciation or environmentally induced plasticity. Specimens of an acanthocephalan parasite, Leptorhynchoides thecatus, collected throughout North America were analysed phylogenetically using sequences of the cytochrome oxidase I gene and the internal transcribed spacer region. Variation in host use, habitat use, and transmission were examined in a phylogenetic context to determine if they were more likely phylogenetically based or due to environmental influences. Results indicated that most of the variation detected can be explained by the presence of cryptic species. The majority of these species have narrow host and microhabitat specificities although one species, which also may comprise a complex of species, exhibits broad host and habitat specificity. Alternate transmission pathways only occurred in two of the cryptic species and correlate with host use patterns. Taxa that mature in piscivorous piscine hosts use a paratenic fish host to bridge the trophic gap between their amphipod intermediate host and piscivorous definitive host. One potential example of environmentally induced variation was identified in three populations of these parasites, which differ on their abilities to infect different host species.

Alternate JournalMol. Ecol.