Phylogenetic Relationships of Noturus Stanauli and N. Crypticus (Siluriformes: Ictaluridae), Two Imperiled Freshwater Fish Species from the Southeastern United States
Noturus stanauli and N. crypticus are two madtom catfish species of conservation concern with very restricted distributions in the Upper Tennessee River Drainage and Duck River. A recent phylogenetic analysis of Noturus using mtDNA sequences did not include these species. A new phylogenetic analysis of cytochrome b sequences including N. stanauli and N. crypticus is presented. Both maximum parsimony and Bayesian analyses indicate that N. stanauli and N. crypticus are closely related and nest within a genetically divergent clade comprising N. fasciatus, N. baileyi, N. elegans, and a paraphyletic N. hildebrandi. Limited intraspecific sampling of N. stanauli and N. crypticus revealed few genetic differences within these species. We discuss our results in the context of conservation status of these species and the use of phylogenetic trees and sequence data in the delimitation of cryptic species diversity in Noturus.Abstract
Strict consensus of 96 trees resulting from maximum parsimony analysis of the ictalurid cytochrome b alignment. Noturus stanauli and N. crypticus are highlighted with a box. The most recent common ancestor of the Noturus hildebrandi species clade is marked with a black dot. Only relationships among Noturus species are shown. Numbers at nodes report percent recovery in bootstrap pseudoreplicate analysis.
Fifty percent majority rule consensus phylogram resulting from Bayesian analysis of the ictalurid cytochrome b alignment. Only relationships among Noturus species are shown. Noturus stanauli and N. crypticus are highlighted with a box. The most recent common ancestor of the Noturus hildebrandi species clade is marked with a black dot. Asterisks at nodes indicate a 95% or greater Bayesian posterior probability.
Contributor Notes
(TJN) Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996-1610; and (MH)Finnish Forest Research Institute, Jokiniemenkuja 1, Pl 18, Fin-01301 Vantaa, Finland. Present Address: (TJN) Department of Ecology And Evolutionary Biology, Yale University, New Haven, Connecticut 06520. E-mail: (TJN) thomas.near@yale.edu. Send reprint requests to TJN.