ABSTRACT
The identication of taxa and discernment of evolutionary relationships within the family Dreissenidae have been confounded by morphological plasticity as well as prior lack of a comprehensive DNA sequence data analysis. We thus analyzed the phylogenetic relationships of putative taxa (species and subspecies) in the genus Dreissena in relation to its nearest living relatives (Mytilopsis leucophaeata and Congeria kusceri) using DNA sequence data from the nuclear 28S RNA gene and three
mitochondrial genes: cytochrome c oxidase subunit I (COI), 16S RNA, and cytochrome (cyt) b oxidase. Relationships resolved by maximum likelihood and Bayesian phylogenetic trees are robust and congruent and support division of Dreissena into three subgenera: Dreissena, Pontodreissena, and Carinodreissena. The subgenus Pontodreissena contains two species: Dreissena caputlacus and Dreissena rostriformis. Putative subspecies once proposed for D. rostriformis lack genetic divergence and likely should no longer be recognized; these include D. r. “bugensis” (the quagga mussel),
Carol A. Stepien, Igor A. Grigorovich, Meredith A. Gray, Timothy J. Sullivan, Shane Yerga-Woolwine, and Gokhan Kalayci
CONTENTS
Abstract ................................................................................................................................................................................ 403 Introduction .......................................................................................................................................................................... 404
Evolutionary Relationships of the Dreissenidae: Dreissena, Mytilopsis, and Congeria ................................................ 404 Biogeography of Dreissenids in Relation to Geologic Events ........................................................................................ 406 Background and Evolutionary Questions about Dreissena ............................................................................................ 407
Methods ............................................................................................................................................................................... 409 Results and Discussion..........................................................................................................................................................421
