Steven L. Powers

Etheostoma cervus: A New Species from the Forked Deer River System in Western Tennessee with Comparison to Etheostoma pyrrhogaster (Percidae: Subgenus Ulocentra)

Abstract Analysis of 27 standard and truss measurements, 15 meristic characters, and coloration of the Etheostoma pyrrhogaster species complex across its range supported the recognition of two allopatric and diagnosable species within this complex. The previously described E. pyrrhogaster and Etheostoma cervus, a new species described herein, are endemic to the Obion and Forked Deer River systems, respectively, in western Kentucky and Tennessee. The two species differ in pigmentation of nuptial males with E. pyrrhogaster having extensive turquoise pigmentation in dorsal, anal, and pelvic fins, whereas E. cervus lacks extensive turquoise pigmentation in these fins. The ventral portion of the head of nuptial male E. pyrrhogaster has a green cast, whereas this area in nuptial male E. cervus is straw colored. Lateral-line scales are modally 42 in E. pyrrhogaster and 39 in E. cervus. Interorbital width and body depth are also greater in E. pyrrhogaster than in E. cervus.

Conservation Genetics of the Ashy Darter, Etheostoma cinereum (Percidae: Subgenus Allohistium), in the Cumberland and Tennessee Rivers of the Southeastern United States

Abstract The Ashy Darter, Etheostoma cinereum (Percidae: subgenus Allohistium), is restricted to flowing pools of relatively silt free, medium-sized rivers in the Cumberland, Duck and Tennessee River drainages in the southeastern United States. Degradation of these habitats within these drainages has fragmented the range of E. cinereum into several disjunct populations and eliminated it from many historical localities. Phylogenetic analysis of cytochrome b sequence from individuals (n = 14) representing each of the extant populations of E. cinereum indicated genetic differentiation among populations inhabiting the Cumberland, Duck, and upper Tennessee River drainages. These analyses are concordant with previously noted patterns of morphological variation and minimally support three different management units (MU) currently recognized as E. cinereum. Efforts to conserve these distinct MUs should be considered in management attempts.

Life-History Aspects of the Cherokee Darter, Etheostoma scotti (Actinopterygii: Percidae), an Imperiled Species in Northern Georgia

Abstract Aspects of the life-history of Etheostoma scotti (Cherokee Darter) were investigated using 12 monthly collections from Hickory Log Creek (Etowah River Drainage) in Cherokee County, GA. Specimens were collected from riffles, runs, and pools with slow current and examined to illuminate age, growth, food habits, and reproductive characters. The bulk of the diet consisted of Chironomidae larvae, with mollusks, detritus, branchiopods, and other aquatic insects as smaller components. Peak feeding occurred in late winter and spring and immediately preceded gamete production for a single spring spawning season peaking in April. Gravid females, collected from March to June, contained 2–256 mature oocytes, ranging from 0.7 to 1.2 mm in diameter. Sexual maturity occurred at age 1, and maximum age was 2 years. The largest specimen collected was a male 49.1 mm SL and 2.0 g total weight. Males were larger than females and were outnumbered 1:1.56. Only about half of the adult-sized males appeared to be in nuptial condition during the spawning season in the study population. These findings provide a greater understanding of the biology of this imperiled species and may allow for more focused and effective conservation efforts.

Phylogeography of Three Snubnose Darters (Percidae: Subgenus Ulocentra) Endemic to the Southeastern U.S. Coastal Plain

Abstract The Yazoo Darter, Etheostoma raneyi (Percidae: subgenus Ulocentra), is a narrowly restricted endemic occurring in small tributaries in the Loessial Hills of the upper Yazoo River basin in northern Mississippi. The range of the species is shared between the Little Tallahatchie and adjacent upper Yocona rivers, but populations in the two rivers are separated by unsuitable habitat in the Mississippi Alluvial Plain. The Chickasaw Darter, Etheostoma cervus, and Firebelly Darter, E. pyrrhogaster, show analogous distributions in the Forked Deer and Obion rivers, respectively, of western Tennessee and Kentucky. Phylogenetic analyses of cyt b and control region mtDNA (1497 sites) data from E. raneyi (n  =  12), E. cervus (n  =  4), and E. pyrrhogaster (n  =  5) recovered two clades of E. raneyi with high bootstrap and decay support that are congruent with localities of specimens from the Little Tallahatchie and Yocona drainages, respectively. Divergence between the clades of E. raneyi was 1.3% (SE  =  0.3%). Within drainage divergence was 0.3% (SE  =  0.1%) for the Little Tallahatchie clade and 0.1% (SE < 0.1%) for the Yocona clade. Etheostoma cervus and E. pyrrhogaster showed interspecific divergence of 1.3% (SE  =  0.2%) and intraspecific divergence of 0.7% (SE  =  0.2%) and 0.8% (SE  =  0.2%), respectively. These results suggest isolation by vicariance as a mode of speciation in fishes restricted to the Upper Coastal Plain. Conservation action may be in order for E. raneyi as populations from the Little Tallahatchie and Yocona rivers should be treated as separate management units with the latter known from only five small streams, some of which are threatened by encroaching development.

Life -history Aspects of Hypentelium etowanum (Alabama Hog Sucker) (Actinopterygii: Catostomidae) in Northern Georgia

Abstract Life-history aspects of Hypentelium etowanum (Alabama Hog Sucker) were investigated from 12 monthly collections in Shoal and Moore creeks (Etowah River Drainage) in Cherokee County, GA. Specimens were collected primarily from riffles, runs, and flowing pools, and examined for age, growth, food habits, and reproductive cycle. Chironomidae composed the bulk of the diet, with consumption lowest in winter and peaking in spring. Spawning appeared to occur in spring with 493–2717 ripe eggs ranging from 1.5 to 2.8 mm in diameter present in specimens collected in March, April, and May. Sexual maturity appeared to occur by 3 years of age, with a maximum lifespan of greater than 4 years. The largest specimen collected was a female 190 mm standard length and 132 g total weight.

Status of the Noturus elegans Species Complex in the Middle and Upper Tennessee River Drainage

Abstract Three independent surveys for undescribed members of the Noturus elegans species complex in the middle and upper Tennessee River drainage were conducted between 1993 and 2001. These surveys encompassed 104 collections made at 92 sites in Alabama and Tennessee. A total of 10 chucky madtoms was captured from two upper Tennessee River localities on Little Chucky Creek, Greene County, TN. Nine of these specimens were collected in September 1994, and the tenth in March 2000. No specimens were captured during three visits to Little Chucky Creek in 2001. No N. elegans species complex madtoms were collected in the middle Tennessee River drainage. Additional work is required to demonstrate the continued existence of these extremely rare fishes before recovery measures can be implemented.

Life-history Aspects of Notropis xaenocephalus (Coosa Shiner) (Actinopterygii: Cyprinidae) in Northern Georgia

Abstract The biology of Notropis xaenocephalus (Coosa Shiner) was investigated using 12 monthly collections from Moore Creek (Etowah River Drainage) in Cherokee County, GA. Specimens were collected primarily from pools with slow current and examined to determine age, growth, food habits, and reproductive cycle. The bulk of the diet consisted of Diptera adults, Chironomidae larvae, Hymenoptera, and unidentified insect parts. Feeding was greatest in the spring and lowest during winter months. Spawning occurred in spring to early summer, with 86–540 mature oocytes ranging from 0.9 to 1.3 mm in diameter present in specimens collected from March to June. Sexual maturity occurred at 1 year of age. The largest specimen collected was a female 63.8 mm SL and 4.4 g total weight. Two specimens estimated to be 38 months of age were the oldest specimens collected. As one of the most abundant minnows in the upper Alabama River Drainage, these findings provide a greater understanding of the ecology of this imperiled ecosystem.

Life-History Aspects of the Rainbow Shiner, Notropis chrosomus (Teleostei: Cyprinidae), in Northern Georgia

Abstract The life history of Notropis chrosomus (Rainbow Shiner) was investigated using 12 monthly collections from Moore Creek (Etowah River Drainage) at GA Highway 140 in Cherokee County, GA. Specimens were collected by electroshocking and seining primarily from runs and flowing pools and examined to identify feeding habits, age, growth, and reproductive patterns. Notropis chrosomus are opportunistic insectivores with gut contents largely consisting of Chironomidae larvae, unidentified insect parts, unidentified Diptera adults, and Collembola. Spawning occurred in spring with 400–896 (mean 708.92, SD = 162.90) mature oocytes ranging from 0.7 mm to 1.22 mm (mean = 0.90 mm, SD = 0.167 mm) present in specimens collected in April, May, and June. Sexual maturity occurred at approximately one year of age. The maximum age of both males and females was estimated at approximately 24 months (females = 25 months, males = 23 months). The largest female collected was 66.71 mm SL and 5.515 g total weight. The largest male collected was 60.19 mm SL and 3.691 g total weight.

Life-History Aspects of Fundulus stellifer (Southern Studfish) (Actinopterygii: Fundulidae) in Northern Georgia

Abstract Fundulus stellifer (Southern Studfish) was studied using 12 monthly collections from Moores Creek near Waleska, GA. Female specimens ranged from 24.72 mm to 94.29 mm SL and up to 15.90 g total weight. Male specimens ranged from 27.81 mm to 96.07 mm SL and up to 18.60 g total weight. Increases in size were greatest in spring and summer. Maximum age appears to be just over 2 years for both sexes, as the oldest specimens collected were estimated at 28 months of age. Spawning likely occurred between late April and early June. Sexual maturity was reached in the second full spawning season for both sexes, with females having a maximum ova diameter of 2.75 mm. The primary diet of F. stellifer consisted of Chironomidae, Branchiopoda, and unidentified insect parts, with other food items seasonally. The amount of food consumed is greatest in the months preceding and during spawning and lowest during fall and early winter.

Testing for Genetic Divergence within and among Isolated Populations of a Threatened Species in Georgia and Alabama, Percina aurolineata (Percidae; Goldline Darter)

Abstract Percina aurolineata (Percidae: subgenus Hadropterus) (Goldline Darter) is a federally threatened species that currently exists in disjunct populations in the Coosawattee River, GA, and Cahaba River, AL. These 2 Mobile Basin drainages are home to considerable endemism, and these disjunctions may actually represent cryptic diversity within Goldline Darter. We examined sequence data from the mitochondrial cytochrome b gene (cyt b) and nuclear recombination-activation gene exon 1 (RAG1) from specimens (n = 34) collected from 4 streams in the Coosawattee River drainage and 4 streams in the Cahaba River drainage for the purpose of assessing phylogenetic structure and genetic divergence to test the hypothesis that the disjunct populations of Goldline Darter represent a single species. Specimens from each of the rivers sampled were not resolved as a clade in any analysis. For cyt b, divergence within the Coosawattee was 0.8%, divergence within the Cahaba was 0.3%, and net divergence between populations was 0.4%. For RAG1, divergence within the Coosawattee was 0.0%, divergence within the Cahaba was 0.1%, and net divergence between populations was 0.0%. We detected a unique allele for RAG1 with a frequency of 0.559 in the Cahaba specimens. No clades were resolved that contained specimens representative of only one locality and the difference between mean divergence among and within rivers was low; thus, these results support the hypothesis that the disjunct populations of Goldline Darter represent a single species and an evolutionarily significant unit. The divergence of allele frequencies among Cahaba and Coosawattee for RAG1 qualifies them as separate management units, and future conservation efforts should manage them as such.