“Forms” of water mites (Acari: Hydrachnidia): intraspecificvariation or valid species?
2013 (English)In: Ecology and Evolution, ISSN 2045-7758, Vol. 3, no 10, 3415-3435 p.Article in journal (Refereed) Published
In many groups oforganisms, especially in the older literature, it has been common practice torecognize sympatrically occurring phenotypic variants of a species as "forms".However, what these forms really represent often remains unclear, especially inpoorly studied groups. With new algorithms for DNA-based species delimitation,the status of forms can be explicitly tested with molecular data. In this study,we test a number of what is now recognized as valid species of water mites(Hydrachnidia), but have in the past been treated as forms sympatricallyoccurring with their nominate species. We also test a form without priortaxonomical status, using DNA and morphometrics. The barcoding fragmentof COI, nuclear 28S and quantitativeanalyses of morphological data were used to test whether these taxa merit speciesstatus, as suggested by several taxonomists. Our results confirm valid species.Genetic distances between the form and nominate species (Pionadispersa and Pionavariabilis, COI 11%), as well as likelihood ratio tests underthe general mixed Yule coalescent model, supported that these are separatelyevolving lineages as defined by the unified species concept. In addition, they canbe diagnosed with morphological characters. The study also reveals that sometaxa genetically represent more than one species. We propose that P. dispersaare recognized as valid taxa at the species level. Unionicola minor (which may consist of several species), Piona stjordalensis, P. imminuta s. lat. and P. rotundoides are confirmed as speciesusing this model. The results also imply that future studies of other watermite species complexes are likely to reveal many more genetically andmorphologically distinct species.
Place, publisher, year, edition, pages
2013. Vol. 3, no 10, 3415-3435 p.
Bayesian analysis, cryptic species, DNA barcoding, GMYC model, principal Pcomponent analysis, species delimitation
IdentifiersURN: urn:nbn:se:su:diva-94304DOI: 10.1002/ece3.704OAI: oai:DiVA.org:su-94304DiVA: diva2:653000
ProjectsDoktorandprojekt "Taxonomi och fylogeni hos vattenkvalster och sammetskvalster (Acari)