Two new species of Noturus (Siluriformes : Ictaluridae) from the Tennessee River drainage: Description, distribution, and conservation status

摘要

Nominotypical Noturus elegans are herein restricted to the Green River drainage of central Kentucky and north-central Tennessee. Ten specimens and additional new material from the Duck River originally allocated to N. elegans are here described as a new species, Noturus fasciatus, restricted to the Duck River system and two minor tributaries of the lower arm of the Tennessee River, Tennessee. A second new species, Noturus crypticus, is described from the only known extant population in Little Chucky Creek, Greene County, Tennessee. These three taxa are closely related and are distinguished on the basis of modal differences in anal-fin ray numbers, body shape, pigmentation, and genotypic arrays. Noturus crypticus is described from only eight specimens, is clearly uncommon, probably relict, and in need of federal protection and future propagation efforts. All three species are primarily riffle/glide dwellers in small- to medium-sized streams where they may be found in or under gravel, rubble, and slab rock. The limited geographic distributions of the two new species places them at greater risk of extinction, warranting comprehensive evaluation of their life histories, demographic characteristics, recruitment rates, and nesting requirements.