••• 11111111 ••• ••• ... .... ... ••• ALABAMA MUSEUM of Natural History Bulletin 25 August 1, 2007 Systematics, Evolution and Biogeography of the Etheostoma simoterum Species Complex (Percidae: Subgenus Ulocentra) Distribution and Satus of Freshwater Mussels (Bivalvia Unionidae) of the Lower Coosa and Tallapoosa River Drainages in Alabama The Osteology of the Stonecat, Noturus flavus (Siluriformes: Ictaluridae), with Comparisons to Other Siluriforms 8 1 BULLETIN ALABAMA MUSEUM OF NATURAL mSTORY The scientific publication of the Alabama Museum of Natural History. Dr. Phillip Harris, Editor. BULLETIN AlABAMA MUSEUM OF NATURAL HISTORY is published by the Alabama Museum of Natural History, a unit of The University of Alabama. The BULLETIN succeeds its predecessor, the MUSEUM PAPERS, which was terminated in 1961 upon the transfer of the Museum to the University from its parent organiza­ tion, the Geological Survey of Alabama. 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Evolution and Biogeography of the Etheostoma simoterum Species Complex (Percidae: Subgenus Ulocentra) Steven L. Powers and Richard L. Mayden (SLP) Department of Biology, Reinhardt College, Waleska, Georgia 30183-2981 E-mail: [email protected] Phone: (770) 720-9220 Fax: (770) 720-5602 (RLM) Department of Biological Sciences, St. Louis University, St. Louis, Missouri 63103-2010 E-mail: [email protected] Phone: (314) 977-3494 Fax: (314) 977-3658 Abstract Etlieostollla sillloterlllll and Etlieostoll/a atripill1le were the first two described species now contained within subgenus Ulocelltra (Actinopterygii: Percidae). Due to hypothesized intergradation resulting in an informal synonymy, the two taxa have been considered conspecific since the early 1980s. This synonymy made Etlieostollla sill/oterllll/ the most widely distributed of the snubnose darters. An investigation of meristic, morphometric, and pigmentation of nuptial males indicated that multiple species are present within the Etlieostoll/a sill/oterlllll species complex. Unique combinations of breast, abdomen, caudal peduncle, mouth, dorsal fin and lateral pigment characters indicate six morphologically diagnosable species restricted to the following drainages: 1. upper Holston and Russell Fork river drainages, 2. Tennessee River tributaries exclusive of the Duck and upper Holston rivers, 3. Duck River and tributaries, 4. Cumberland River tributaries on the western Highland Rim, 5. Cumberland River tributaries in the Nashville Basin, and 6. Cumberland River tributaries on the Eastern Highland Rim. Meristic, morphometric, and biogeographic data also provide various levels of support for the recognition of these species. Phylogenetic analyses of 1337 bp of mtDNA from 25 individuals representing all species of the complex described herein indicated that lineages within the complex had not reached coalescence, with the exception of E. sillloterlllll. This incomplete lineage sorting would be expected due to the presumably recent speciation of these taxa and extremely large population sizes of most members of the com­ plex. The overall phylogenetic and biogeographic pattern revealed by the analyses indicated that the Duck River endemic was sister to all other mem­ bers of the complex. Relationships of the other species of the complex were largely unresolved with the exception of species from the Cumberland representing a clade sister to the species primarily restricted to the Tennessee River. Biogeographic concordance with other species of fishes and lack of coalescence of most lineages within the complex indicated that vicariance has been the predominant mode of speciation for the species within the E. sill/oterlllll complex. Distributions of other species found in the Cumberland and upper Tennessee but absent from the Duck River system support the hypothesized sister relationship of the Duck River endemic to all other members of the E. sillloterllll/ species complex. Introduction Etheosto11lrl si11loterll11l was described by Cope (1868) scribed E. atTijJimu' from "a tributary to the Cumberland from the "Holston River and its tributaries." Specific lo­ River, near Nashville." Etnier (1980a) indicated that E. calities sampled by Cope were in the North and Middle atTijJinne inhabited Cumberland River tributaries down­ forks of the Holston and their tributaries. Etnier (1980b) stream of Cumberland Falls. Confusion of these two indicated that the range of E. si11loterll11l included Russell taxa was illustrated by Page's (1983) indication that E. Fork of the Big Sandy River, the Bluestone River (a tribu­ atTijJinne inhabited the Duck River system rather than E. tary to the Kanawha River), all upper Tennessee River si11lotent11l. tributaries west of North Carolina, northern tributaries Bouchard (1977) examined nine meristic variables to the middle Tennessee River (including Bear Creek in from 70 individuals in seven drainages containing either Alabama), and eastern tributaries to lower Tennessee Etheostoma si11lotent11l or E. atTijJinne and suggested that River including the Duck River drainage, and was largely differences between the two taxa may represent c1inal parapatric with Etheosto11la atrijJinne. Jordan (1877) de- variation. Several authors (Page and Mayden, 1981; Page Bull. Alabama Mus. Nat. Hist. 25:1-23 August 1, 2007 2 BULLETIN 25 ______ August 1, 2007 and Burr, 1982; Etnier and Starnes, 1993; Jenkins and sequence data from specimens collected throughout the Burkhead, 1994) considered E. aLrij)inne only intraspe­ range of the complex. Evolutionary and biogeographic cifically different from E. simoterwlI, based largely on the hypotheses can then be inferred from the results of these data presented by Bouchard (1977). This synonymy left E. analyses. alri/)inn!' a subspecies within E. simoLermn with the former inhabiting the Duck and Cumberland river systems, the latter in the Tennessee River system upstream of and in­ Methods cluding the Paint Rock River, and an hypothesized zone Morphological analyses of intergradation in the Tennessee River system between Variation of the Etlwosto'lll(l simolernln species complex the mouths of the Duck and Paint Rock rivers (Etnier and was evaluated using meristic characters following Hubbs Starnes, 1993). and Lagler (1947) except as follows: transverse scales were Descriptions of life colors also vary dramatically counted from the origin of the anal fin anteriodorsally to among authors working with populations in different the base of the spinous dorsal fin; prepectoral scales were regions inhabited by ELhl'osloma simoll'rwn. Breast color counted as all scales anterior to the pectoral fin origin and was described as black by Jenkins and Burkhead (1994) posterior to the operculum; saddles and lateral blotches and orange by Etnier and Starnes (1993). Page (1983) were counted as enlarged areas of dark pigment dorsally and Mettee et al. (1996) distinguished E. simoLl'rllln from and along the lateral line, respectively; and interblotch the sympatric E. dW)li by lateral blotches separate rather red spots were counted as distinct red spots dorsal to the than fused into a midlateral stripe. In contrast, Jenkins lateral line on the interblotch area immediately ventral to and Burkhead (1994) described the lateral pigment of the origin of the soft dorsal fin of nuptial males. Interra­ E. si1lloter'llln as a black stripe. Page (1983) also described dial membranes of the spinous dorsal fin posterior to the E. aLri/)inn!' as being "deep green or blue-green overall", anterior-most membrane (IRM 2-n) in nuptial males were while Etnier and Starnes (1993), Jenkins and Burkhead coded to quantify the variation of red pigment in the fin (1994), and