title: Genetic structure in a progenetic trematode: signs of cryptic species with contrasting reproductive strategies.
abstract: Complexes of cryptic species are rapidly being discovered in many parasite taxa, including trematodes. However, after they are found, cryptic species are rarely distinguished from each other with respect to key ecological or life history traits. In this study, we applied an integrative taxonomic approach to the discovery of cryptic species within Stegodexamene anguillae, a facultatively progenetic trematode common throughout New Zealand. The presence of cryptic species was determined by the genetic divergence found in the mitochondrial cytochrome c oxidase I gene, the 16S rRNA gene and the nuclear 28S gene, warranting recognition of two distinct species and indicating a possible third species. Speciation was not associated with geographic distribution or microhabitat within the second intermediate host; however frequency of the progenetic reproductive strategy (and the truncated life cycle associated with it) was significantly greater in one of the lineages. Therefore, two lines of evidence, molecular and ecological, support the distinction between these two species and suggest scenarios for their divergence.
authors: Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand; Department of Biological Sciences, Tarleton State University, Box T-0100, Stephenville, TX 76402, USA. Electronic address: herrmann@tarleton.edu.
authors: K K
authors: KK
authors: Herrmann
authors: Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand.
authors: R
authors: R
authors: Poulin
authors: Department of Biological Sciences, Le Moyne College, Syracuse, NY 13214, USA.
authors: D B
authors: DB
authors: Keeney
authors: Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand.
authors: I
authors: I
authors: Blasco-Costa
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006239:Haplotypes; D009520:New Zealand; D013045:Species Specificity; D014200:Trematoda / Q000145:classification / Q000235:genetics*
keywords: Abbreviated life cycles; Eel parasite; Speciation; Stegodexamene anguillae; Trematodes