Thursday, April 18, 2013

New Darter Species from Tennessee’s Caney Fork River


A new species of fish only found in the state of Tennessee was scientifically described this month and was named after a co-author of The Fishes of Tennessee book. The new species was formerly considered an isolated population of the Bloodfin Darter Etheostoma (Nothonotus) sanguifluum, which is otherwise widespread in medium-sized creeks throughout the middle Cumberland River drainage in Kentucky and Tennessee.

The Bloodfin Darter, Etheostoma sanguifluum (or Nothonotus sanguifluus, see below) from the middle Cumberland River drainage in Kentucky and Tennessee. C) male and D) female. From figure 3 in Keck and Near 2013.
 
Ben Keck at the University of Tennessee and Tom Near at Yale University described the new species based on differences in male nuptial coloration and scale counts.  The new species is the Caney Fork Darter Nothonotus starnesi, restricted to the Caney Fork River system above Great Falls in Grundy, Van Buren, Warren, and White counties near McMinnville Tennessee. It is named after Wayne Starnes, co-author of the Fishes of Tennessee and Curator of Fishes at the North Carolina Museum of Natural History, for his contributions on the natural history and biology of North American freshwater fishes.
 
The Caney Fork Darter, Nothonotus starnesi, from the Caney Fork River system above Great Falls near McMinnville Tennessee Photo of nuptial male by Dave Neely.

The Caney Fork Darter, like many other darters, displays sexual dimorphism which is most pronounced during the breeding season (May-July), with males having bright red spots on their sides and red and blue in their fins. The species occupies fast-flowing riffles over large cobble and small boulders in medium to large streams. Most populations appear stable, but the Caney Fork Darter’s restricted range, impoundment of habitat by the Great Falls reservoir, and threats from intensive silviculture, livestock production, urbanization, and invasive species put this species at risk and may require future conservation efforts.
The Caney Fork Darter, Nothonotus starnesi, from the Caney Fork River system above Great Falls near McMinnville Tennessee E) male and F) female. From figure 3 in Keck and Near 2013




The taxonomy of the scientific names of the Bloodfin and Caney Fork darters and their close relatives is undergoing changes. These species, as well as some twenty other species, were previously placed in the subgenus Nothonotus within the genus Etheostoma (Etnier and Starnes 1993). Molecular studies based on a mitochondrial gene indicated that the subgenus was more closely related to other darter genera, leading Near and Keck (2005) to elevate Nothonotus to the generic level, which changed the ending on the specific epithet of many species to match the gender of the new genus (e.g. sanguifluum to sanguifluus).  Later molecular studies using nuclear genes in combination with mitochondrial genes (Near et al. 2011) or nuclear genes alone (Near and Keck 2013) showed that Nothonotus and Etheostoma are sister taxa, therefore some ichthyologists retain the genus Etheostoma for these darters while others recognize Nothonotus as a distinct genus.
Distribution of the Caney Fork Darter, Nothonotus starnesi, and other closely-related species in the Cumberland River drainage in Kentucky and Tennessee From figure 2 in Keck and Near 2013.
Citation for species description:
Keck, B.P., and T.J. Near. 2013. A new species of Nothonotus darter (Teleostei: Percidae) from the Caney Fork in Tennessee, USA. Bulletin of the Peabody Museum of Natural History 54:3-21.
 
Other citations:
Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press, Knoxville.
 
Near, T.J., C.M. Bossu, G.S. Bradburd, R.L. Carlson, R.C. Harrington, P.R. Hollingsworth Jr., B.P. Keck, and D.A. Etnier. 2011. Phylogeny and temporal diversification of darters (Percidae: Etheostomatinae). Systematic Biology 60:565-595.
 
Near, T.J., and B.P. Keck. 2013. Free from mitochondrial DNA: nuclear genes and the inference of species trees among closely related darter lineages (Teleostei: Percidae: Etheostomatinae). Molecular Phylogenetics and Evolution 66:868-876.
 
Near, T.J., and B.P. Keck. 2005. Dispersal, vicariance, and timing of diversification in Nothonotus darters. Molecular Ecology 14: 3485-3496.