Habitat alteration and its effects on native fishes in the upper Tennessee River system, east-central U.S.A.

The upper Tennessee River drainage, which includes portions of the States of Virginia, North Carolina, and Tennessee, supports an exceptionally diverse fish fauna. Recent reductions in abundance and geographic ranges of several freshwater fishes have promulgated the imposition of protective measures for about 115 species among the three states, with nearly half of those species occurring in the upper Tennessee River. Most protected species are darters (Percidae: Etheostomatinae) or minnows (Cyprinidae), and are typically small, benthic invertivores. Major impacts on the fish fauna have resulted from dams, introduced species, toxic spills, mining and agriculture. An important cumulative effect of these impacts is fragmentation of the watershed; nearly 40% of the riverine habitat in major tributaries is either impounded or altered by tailwater discharges. The isolation and stress imposed on tributaries of the river have caused and will continue to cause extirpations of fishes, mussels and other aquatic fauna. Numerous federal, state, and private organizations are co-operating in efforts to protect rare species and habitats, improve agricultural and coal-producing practices, and enforce regulations for industrial and municipal effluents.     

Importance of phytoplankton carbon to heterotrophic bacteria in the Ohio,Cumberland, and Tennessee rivers,USA

The flux of carbon and nutrients through aquatic systems is largely dependent upon interactions between autotrophic and heterotrophic processes. As a means of assessing the relative importance of autotrophy and heterotrophy in large rivers, we compared phytoplankton production, heterotrophic bacterial production and community respiration in three regulated rivers of the Midwestern USA. Samples were collected monthly (March to December 1999) from impoundments of the Ohio (McAlpine Pool), Cumberland (Lake Barkley), and Tennessee (Kentucky Lake) Rivers. Bacterial production was tightly coupled to phytoplankton production at each site (r ² = 0.63–0.85). Ratios of phytoplankton production to bacterial production ranged from <1 to 15 in the Tennessee and Cumberland Rivers and 2 to 90 in the Ohio River. The ratio of primary production to community respiration (P:R) ranged from 0.03 to 2.76 across all sites, with average P:R values lower in the Ohio River (0.14) than the Tennessee River (0.39) and the Cumberland River (1.10). P:R values above unity (P > R) were observed only in the Tennessee and Cumberland Rivers during seasonal (April–July) spikes in primary production. We estimate that 3, 6, and 20% of annual bacterial carbon requirements were met by exudates from in situ phytoplankton in the Ohio River, Tennessee River, and Cumberland River, respectively. Our findings indicate that heterotrophic bacteria were largely dependant upon allochthonous carbon. Autochthonous sources provided supplemental organic matter (up to 40% of bacterial carbon demand) during summer low flow. Handling editor: J. Padisak     

Genic variation in the coyote,Canis latrans,in Tennessee,U.S.A.

Protein variation, levels of heterozygosity, and interlocality gene variation were studied in the coyote, Canis latrans, using starch gel electrophoresis. Canis latrans were obtained from 27 counties in Tennessee. Eleven of 20 loci examined were found to be polymorphic with the remaining nine loci fixed for the same gene in all populations. Mean heterozygosity (\-H) varied from 0.0% to 1.9% with a mean of 0.9%. These values are low for a mammal. Significant heterozygote deficiencies occurred in most groups. Results of F-statistics indicated a significant degree of population differentiation at four loci (Gdh, Idh-1, Mdh-2, 6-Pgd). Rogers' coefficients of genetic similarity ranged from 0.950 to 1.000 and showed C. latrans to be genetically homogenous in that portion of the range investigated.     

Two new species of tardigrades from Short Mountain, Tennessee, U.S.A.

Tardigrades were collected from three seepage spring sites at 549m on Short Mountain, Cannon County, Tennessee. Three terrestrial samples and three aquatic samples were taken monthly from each site. Terrestrial samples included mosses and lichens from rocks and fallen trees; one sample of leaf litter was also collected from two of the sites. Aquatic samples included sediment, decaying leaf litter, and aquatic plants. Specimens of tardigrades were mounted on individual slides in Hoyer's medium. Species were identified and photographed using phase and differential contrast microscopy. Twenty-eight species representing 13 genera were recorded: Pseudechiniscus, Echiniscus, Doryphoribius, Ramazzottius, Hypsibius, Isohypsibius, Dipliascon, Platicrista, Itaquascon, Murrayon, Macrobiotus, Minibiotus , and Milnesium. One of the Pseudechmiscus species and an Isohypsibius species were new to science and are described in this paper.     

Phytoplankton growth in the Ohio, Cumberland and Tennessee Rivers, USA: inter-site differences in light and nutrient limitation

Seasonal patterns in resource limitation of phytoplankton growth were assessed monthly within three large rivers with differing extents of water regulation. The Ohio River is regulated by low dams that do not substantially modify discharge, while the Cumberland and Tennessee Rivers are impounded by a series of high dams to enhance water storage for downstream flood control. Laboratory dilution assays with light and nutrient manipulations indicated that light was the main factor limiting phytoplankton growth at irradiances below 7 E m^–2 d^–1. Light limited growth was frequent in the turbid, higher discharge of the Ohio River, but was rare in the heavily regulated Tennessee and Cumberland Rivers. When irradiance exceeded 7 E m^–2 d^–1, phytoplankton were either P-limited (Cumberland River), co-limited by P and N (Tennessee River), or Si limited (Ohio River). Site-specific differences in nutrient limitation were consistent with differences in ambient nutrient levels, with the Tennessee and Cumberland Rivers characterized by lower N and P concentrations, and the Ohio River by lower Si. Downstream nutrient depletion was evident in the Ohio River through comparison of an upstream and a downstream site, with nutrient limitation (Si) occurring more frequently downstream. Phytoplankton growth rates at ambient light and nutrient levels ranged from 0.1 to 1.5 d^–1 in the Ohio River and 0.2 to 0.6 d^–1 in the Tennessee and Cumberland Rivers. Growth rates were greatest at the onset of the summer base pool, as light intensities increased and nutrient levels were maximal. Our findings indicate that multiple factors regulate phytoplankton growth in regulated rivers and that spatial complexity may arise from differences in discharge and water aging.     

The spiny rat louse, Polyplax spinulosa, as a parasite of the rice rat, Oryzomys palustris, in North America

The spiny rat louse, Polyplax spinulosa, was collected, as adults and embryonated ova from the rice rat, Oryzomys palustris, a cricetid rodent, in Davidson Co., Tennessee. This sucking louse is typically parasitic on domestic rats, which are murid rodents. Because most sucking lice are normally host specific, such cross-familial host infestation is noteworthy.     

Female Choice by Scent Recognition in the Spotted Cucumber Beetle

In species that demonstrate female choice, geographically distinct populations can vary in their signal‐response behaviors as a result of environmental differences or genetic drift. Observing whether or not females discriminate against males from allopatric populations can establish such signal deviations. Here we compare mating success within and between populations of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) collected from Delaware, Tennessee, Missouri, and New Mexico, USA. A no‐choice cross‐mating experiment was employed to measure female preference for sympatric and allopatric males. While only two of the populations (Tennessee and Missouri) demonstrated statistically significant female preference for sympatric males, this trend was observed in all populations tested. Further, we show that (i) males from Tennessee, Missouri, and New Mexico differ in their scent, (ii) females may use population‐specific scents to discriminate among males, and (iii) females whose antennae have been surgically removed are unable to recognize acceptable mates. New Mexico males, which were never accepted by either Tennessee or Missouri females, became acceptable mates when crowded with Tennessee or Missouri males prior to copulation. We infer that male odor may be an important factor in determining cucumber beetle mating success.     

Self-Help Housing, the Poor, and the State in the Caribbean

Self-Help Housing, the Poor, and the State in the Caribbean. Robert B. Potter and Dennis Conway. eds. Knoxville: University of Tennessee Press, 1997. 299 pp.     

Molecular taxonomy in the dark: evolutionary history, phylogeography, and diversity of cave crayfish in the subgenus Aviticambarus, genus Cambarus

Freshwater crayfish species in the subgenus Aviticambarus (Cambaridae: Cambarus) are restricted to caves along the Cumberland Plateau, the Sequatchie Valley, and the Highland Rim which extend along the Tennessee River in southcentral Tennessee and northern Alabama. Historically, three stygobitic species, Cambarus jonesi, Cambarus hamulatus, and Cambarus veitchorum, comprise this subgenus. We examine species' boundaries and phylogeographic structure of this imperiled Southern Appalachian assemblage to shed light on patterns of cave colonization. We also provide estimates of genetic diversity for conservation status assessment. Using geologic evidence, phylogeographic analyses, and sequence data from five gene regions (two nuclear: Histone H3 and GAPDH and three mitochondrial: 12S, 16S, and CO1 totaling almost 2700 base pairs), we identify two well-supported cryptic species in addition to the three currently recognized taxa. Four of these taxa exhibit low levels of genetic variation both currently and historically, which may indicate local extirpation events associated with geological and river basin changes. Our results also support other recent findings that pre-Pleistocene paleodrainages may best explain the current patterns of aquatic faunal biodiversity in the Southern Appalachians.     

Myths of Ethnicity and Nation: Immigration, Work, and Identity in the Belize Banana Industry

Myths of Ethnicity and Nation: Immigration, Work, and Identity in the Belize Banana Industry. Mark Moberg. Knoxville: University of Tennessee Press, 1997. 218 pp.     

Apteragia pursglovei sp. n. (Trichostrongyloidea: trichostrongylidae) from the white-tailed deer, Odocoileus virginianus.

Two species of Apteragia were found in white-tailed deer (Odocoileus virginianus) from 152 counties in 13 southeastern states. Specimens previously reported as Skrjabinagia odocoilei were reidentified as belonging to 2 similar species of the genus Apteragia, A. odocoilei, and A. pursglovei sp. n. Apteragia pursglovei sp. n. is differentiated primarily by the length, conformation, and degree of sclerotization of the spicules. Of the 824 deer, A. odocoilei occurred in 76.5%, A. pursglovei in 13.8%, both species in 5.0%, and neither in 4.7%. Reassessment of distribution data revealed that only A. odocoilei was present in deer from 99 counties, only A. pursglovei in deer from 25 counties, and both species in deer from 28 counties. Both A. odocoilei and A. pursglovei were found in Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, and Virginia. Apteragia odocoilei also occurred in Maryland, Tennessee, West Virginia, Texas, Oklahoma, New Jersey, and the Virgin Islands.     

A new species of Acentrella Bengtsson (Ephemeroptera: Baetidae) from Great Smoky Mountains National Park,USA

Acentrella barbarae sp. n. is described from eggs, larvae, and imagines collected from Great Smoky Mountains National Park, North Carolina and Tennessee, USA. Larvae were collected from cobble-pebble substrate in stream rapids. Life stages were associated by rearing. Eggs have longitudinal chorionic ridges with small, longitudinal furrows. Larvae are distinguished by having segment 3 of the labial palp apically rounded, abdominal terga with posteromedian projections, and tibiae and tarsi with relatively short setae on the outer margins. Imagines are distinguished by the colouration and posterior elevation of abdominal terga. Other Acentrella larvae occur in the same streams as the new species, including A. parvula, which we report from Tennessee for the first time. We provide an updated key to the larvae of North American Acentrella species.     

Deconica cokeriana (Agaricales,Strophariaceae), a new combination

Deconica cokeriana is proposed as a new combination based on morphological and molecular data. This species is fully described, discussed, and illustrated. Until now, D. cokeriana is only known from the eastern USA, specifically from Connecticut, Georgia, Ohio, and Tennessee.     

Sweetgum Dormancy Release: Effects of Chilling, Photoperiod, and Genotype

In Liquidambar styraciflua L., 1200 to 1600 hours of chilling (3°C) resulted in rapid resumption of growth under greenhouse forcing conditions. Long photoperiods were effective substitutes for chilling. Plants from southern Alabama (Lat. 31°) had a lower chilling requirement than those from western Tennessee (Lat. 36°). Growth rate of plants under long photoperiod varied directly with degree of previous chilling.     

Phylogenetic and taxonomic assessment of the endangered Cumberland bean, <Emphasis Type="Italic">Villosa trabalis</Emphasis> and purple bean, <Emphasis Type="Italic">Villosa perpurpurea</Emphasis> (Bivalvia: Unionidae)

Inadequate understanding of the phylogeography, taxonomy, and historical distribution of two critically imperiled freshwater mussels, Cumberland bean, Villosa trabalis, and purple bean, Villosa perpurpurea, has hindered management and recovery actions related to population restoration within their extant ranges. For more than 100 years, the purple-to-pink nacre of V. perpurpurea and white nacre of V. trabalis have been the only defining phenotypic characteristics used to distinguish each species. Genetic samples were analyzed from 140 individuals collected from 10 streams located in Virginia, Tennessee, and Kentucky, representing all known extant populations of each species. A 784-bp section of the mitochondrial DNA ND1 region was sequenced to assess the phylogeography and taxonomic validity of these taxa. Results of our phylogenetic analyses showed 100 % Bayesian posterior support for two distinct clades, one occurring in the Cumberland River basin and the other in the Tennessee River basin, separated by a mean genetic distance of 4 %. Mean genetic distances between haplotypes within each clade was <1 %. Among individuals from the Cumberland River basin, the nacre of shells was white to bluish-white, but in the Tennessee River basin, nacre graded from white to pink to dark purple; thus, nacre color is a variable and inconsistent character in nominal V. trabalis and V. perpurpurea occurring in the Tennessee River basin. Our data suggest that these morphologically similar species do not co-occur, as was previously believed. Instead, we conclude that the two species most likely share a common ancestor, but became isolated within each basin and experienced allopatric speciation. Updates to nomenclature, taxonomic placement, and recovery plans for the investigated species are needed.     

Environmental Pollution: Leaf Cuticular Patterns in Trifolium pratense L.

Red clover populations collected from the polluted environmentsof Memphis, Nashville, and Knoxville (Tennessee) showed decreasedfloral production, low stomatal frequency, high trichome density,and longer trichomes. The results for plant population collectedfrom a less polluted, rural Reelfoot Lake area were quite theopposite. Subsidiary cell complex remained the same in all thepopulations, while stomatal size range showed little variation.     

Development and characterization of 15 polymorphic microsatellite loci isolated from Rafinesque's big-eared bat, Corynorhinus rafinesquii

We developed and characterized 15 microsatellite markers for Rafinesque's big-eared bat, Corynorhinus rafinesquii. In a population from Tennessee, the number of alleles per locus ranged from three to 13 and observed heterozygosities were 0.35 to 0.97 per locus. These loci will provide appropriate variability for estimation of population connectivity, demographic parameters, and genetic diversity for this species of concern.     

Sucking louse (Hoplopleura erratica: Insecta, Anoplura) exchange between individuals of a wild population of Eastern chipmunks, Tamias striatus, in central Tennessee, U.S.A.

Adult Hoplopleura erratica sucking lice were labelled using a setal clipping technique. Host exchange for lice marked in this manner was monitored through a small population of dye-marked Eastern chipmunks, Tamias striatus, the normal host of this ectoparasite, in a deciduous woodland in central Tennessee, U.S.A. This was accomplished by frequent host live-trapping, anaesthetization and pelage examinations. Louse transfer was most prevalent during the host summer mating period, presumably because of increased chipmunk contacts. At this time, 66·7% of marked adult lice within the host population transferred. Exchanges between opposite sex hosts were more common and adult males donated most lice; no juvenile chipmunks were recorded as louse donors. A greater proportion of male than female lice transferred. Using the exclusive boundary strip method, all exchanging chipmunks had overlapping ranges or shared at least one boundary line.     

Description of a new species of Aethycteron Suriano & Beverley-Burton, 1982 (Monogenea: Ancyrocephalidae) on the gills of the rare striated darter,Etheostoma striatulum Page & Braasch (Perciformes: Percidae), from the Duck River,Tennessee, USA

Systematic Parasitology - The striated darter (Etheostoma striatulum Page &amp; Braasch) is a rare fish species restricted to the Duck River system in Maury County, Tennessee, USA. In this...     

Conservation genetics of eastern hellbenders <Emphasis Type="Italic">Cryptobranchus alleganiensis alleganiensis</Emphasis> in the Tennessee Valley

The eastern hellbender has declined across much of its range and is a candidate for listing under the Endangered Species Act. Some of the most viable remaining populations exist in the Southern Appalachian Region in the Tennessee Valley watershed; however these populations are highly isolated and fragmented, and occupy several physiographic provinces, suggesting they may exhibit significant levels of genetic differentiation. We investigated genetic and phylogeographic relationships among eastern hellbender populations across the Tennessee Valley, using nuclear microsatellite markers and mitochondrial sequence data. Our population genetic analyses of microsatellite data revealed a strong pattern of isolation by stream distance, and 4 genetically distinct populations. These four populations were mainly associated with major watersheds, although middle Tennessee samples were difficult to assign to any particular population. Our phylogeographic analysis of mtDNA resulted in a strongly supported monophyletic ingroup containing nine largely allopatric clades, which also largely corresponded to major watersheds. Our findings suggest that hellbenders from different watersheds in the Tennessee Valley should be recognized as genetically distinct populations, and care should be taken to balance the needs of rescuing declining populations with translocation or headstart programs, while also preserving genetic diversity across the region.