Etheostoma Cragini Research Articles

The effects of abiotic enrichment and predator training on the behavior, morphology, and survival of a species of conservation concern

AbstractConservation practitioners often rely on captive breeding programs to supplement wild populations at risk of extinction. While supplementation has been successful for some taxa, the success of using hatchery fish to supplement wild populations is severely impacted by predation. Elevated predation on hatchery fish may arise because hatchery environments often differ from wild environments and constrain the ability of hatchery fish to be adapted to the environments in which they are released. We assessed the effects of abiotic enrichment on the expression of behavioral and morphological phenotypes across three populations of a species of conservation concern, the Arkansas darter (Etheostoma cragini). We also used a factorial approach to assess whether abiotic enrichment and predator training increases survival during encounters with a novel predator. We found that abiotic enrichment affected ecomorphological attributes associated with fins; generally, measures of the caudal and pectoral fin decreased in the treatment group compared to the control treatment. Behaviorally, darters reared with abiotic enrichment increased feeding and decreased movement compared to the control group. Importantly, we found that in combination with predator training, abiotic enrichment increased the probability of surviving first encounters with a predator. We therefore recommend conservation practitioners incorporate abiotic enrichment and predator training in hatchery programs. Captive breeding programs are used to supplement wild populations at risk of extinction, but hatchery‐reared fish often do not survive after release. Using the threatened Arkansas darter, we show that abiotic enrichment and predator training of hatchery populations impact behavior and morphology and increase the probability of surviving first encounters with a non‐native predator.

Assessing Antipredator Behavior and the Potential to Enhance It in a Species of Conservation Concern

AbstractAnimal behavior has the potential to guide the management of populations at risk of extirpation. This includes insights into how animals respond to novel predators and whether those responses can be enhanced to improve survival. Training hatchery‐reared fish to recognize predators has been proposed as a way to reduce postrelease mortalities in the wild. Identifying the presence of innate predator recognition and the capacity for learning to recognize predators in specific species or populations can inform conservation management practices. Here, antipredator behavior (time spent moving and distance from a predator) and the efficacy of predator training were assessed for three populations of a species of conservation concern, the Arkansas Darter Etheostoma cragini, which is vulnerable to predation by esocid predators like the introduced Northern Pike Esox lucius. Arkansas Darters demonstrated some innate ability to recognize and respond to a novel esocid predator and also responded to predator cues (training), although the direction of the response to cues was opposite our prediction. Populations differed in their response to the predator treatment, highlighting the value of managing populations separately. Although the fitness consequences of exposure to predator cues remain to be tested in Arkansas Darters, our results suggest that antipredator behavior is innate and that exposure to predator cues does affect behavior; however, whether or how those behavioral changes affect survival is unclear. This study demonstrates the importance of testing enrichment practices and incorporating behavioral observations into conservation programs to guide population‐specific management decisions.

Rapture-ready darters: Choice of reference genome and genotyping method (whole-genome or sequence capture) influence population genomic inference in Etheostoma.

Researchers studying nonmodel organisms have an increasing number of methods available for generating genomic data. However, the applicability of different methods across species, as well as the effect of reference genome choice on population genomic inference, remain difficult to predict in many cases. We evaluated the impact of data type (whole-genome vs. reduced representation) and reference genome choice on data quality and on population genomic and phylogenomic inference across several species of darters (subfamily Etheostomatinae), a highly diverse radiation of freshwater fish. We generated a high-quality reference genome and developed a hybrid RADseq/sequence capture (Rapture) protocol for the Arkansas darter (Etheostoma cragini). Rapture data from 1,900 individuals spanning four darter species showed recovery of most loci across darter species at high depth and consistent estimates of heterozygosity regardless of reference genome choice. Loci with baits spanning both sides of the restriction enzyme cut site performed especially well across species. For low-coverage whole-genome data, choice of reference genome affected read depth and inferred heterozygosity. For similar amounts of sequence data, Rapture performed better at identifying fine-scale genetic structure compared to whole-genome sequencing. Rapture loci also recovered an accurate phylogeny for the study species and demonstrated high phylogenetic informativeness across the evolutionary history of the genus Etheostoma. Low cost and high cross-species effectiveness regardless of reference genome suggest that Rapture and similar sequence capture methods may be worthwhile choices for studies of diverse species radiations.

Hierarchy theory reveals multiscale predictors of Arkansas darter (Etheostoma cragini) abundance in a Great Plains riverscape

Abstract Landscape ecology and its emphasis on relationships between spatial heterogeneity, scale, and ecological processes can be applied to manage stream ecosystems as riverscapes. Hierarchy theory, a central tenet of riverscape ecology, allows for investigating ecological relationships between aquatic organisms and habitat by exploring the nested interactions inherent in reaches, segments, and basins. Arkansas darter Etheostoma cragini is a Great Plains fish endemic to the Arkansas River basin and is listed as in need of conservation in all five states within its range in North America. The aim of this study was to develop empirical models describing relationships between Arkansas darter abundance and local habitats, and identify the appropriate scale(s) for assessing and managing populations. We used Arkansas darter abundance data collected from stream sample units as a fixed grain size (102 m) and compiled datasets at three hierarchical spatial extents, including reach (103 m), nested within segment (104 m), nested within basin (105 m) in southcentral Kansas. We fit generalised linear mixed models (GLMMs) to assess scale‐specific relationships between Arkansas darter abundance and local habitat dimensions (stream depth and width) and heterogeneity (canopy cover, overhanging vegetation, and woody structure). Habitat parameters included in best‐supported GLMMs differed among extents. Variation in Arkansas darter abundance was explained by canopy cover and channel depth at the reach (54% explained) and segment (56%) extents, and stream width and depth at the basin extent (37%). Partial dependence plots from multiple regression GLMMs revealed that Arkansas darter abundance was negatively correlated with increasing channel depth across all extents, increasing canopy cover at reach and segment extents, and increasing channel width at the basin extent. Our results highlight scale‐specific relationships between Arkansas darter abundance and local habitats across multiple spatial extents. These findings provide direction for assessing stream fish ecology pattern‐process relationships at the appropriate spatial scales and benefit native fish conservation by highlighting the application of hierarchy theory to address management challenges.

Discovery of the Arkansas Darter (Etheostoma cragini) in the Cow Creek Watershed, Cherokee County, Southeastern Kansas

The Arkansas Darter (Etheostoma cragini) is a threatened species in Kansas and was a candidate for threatened status under the Endangered Species Act (1973). The Arkansas Darter's distribution in Kansas includes the Cimarron River basin of southwestern Kansas, the Arkansas River basin in southcentral Kansas, and the Spring River basin (SRB) in southeastern Kansas. Historical surveys in the SRB during the 1960s and 1990s did not detect the Arkansas Darter in the Cow Creek watershed, which is the northernmost tributary of the Spring River. Here we report detection of the Arkansas Darter in three streams of the Cow Creek watershed during August and September 2017, including an unnamed tributary of Cow Creek (eight individuals), the Cow Creek mainstem (one individual), and the Long Branch (five individuals). Although Arkansas Darters were detected in three different streams, collections were all within 1.5 river kilometers of one another. Further, the species was not detected at 26 other locations in the Cow Creek watershed during 2017, indicating a restricted distribution for this fish in this system. This range extension for the Arkansas Darter in the SRB of Kansas may have conservation implications.

Streamflow alteration and habitat ramifications for a threatened fish species in the Central United States

AbstractIn the Central United States, the Arkansas darter (Etheostoma cragini) is listed as a threatened fish species by the State of Kansas. Survival of the darter is threatened by loss of habitat caused by changing streamflow conditions, in particular flow depletion. Future management of darter populations and habitats requires an understanding of streamflow conditions and how those conditions may have changed over time in response to natural and anthropogenic factors. In Kansas, streamflow alteration was assessed at 9 U.S. Geological Survey streamgages in 6 priority basins with no pronounced long‐term trends in precipitation. The assessment was based on a comparison of observed (O) and predicted expected (E) reference conditions for 29 flow metrics. The O/E results indicated a likely or possible diminished flow condition in 2 basins; the primary cause of which is groundwater‐level declines resulting from groundwater pumping for irrigated agriculture. In these 2 basins, habitat characteristics adversely affected by flow depletion may include stream connectivity, pools, and water temperature. The other 4 basins were minimally affected, or unaffected, by flow depletion and therefore may provide the best opportunity for preservation of darter habitat. Through the O/E analysis, anthropogenic streamflow alteration was quantified and the results will enable better‐informed decisions pertaining to the future management of darters in Kansas.

Heirloom genomes and bison conservation American Plains Bison Rewilding an Icon James A. Bailey Farcountry, 2013. 258 pp.

Heirloom genomes and bison conservation <b>American Plains Bison</b> Rewilding an Icon <i>James A. Bailey</i> Farcountry, 2013. 258 pp.

Water availability strongly impacts population genetic patterns of an imperiled Great Plains endemic fish

Genetic, demographic, and environmental pro- cesses affect natural populations synergistically, and understanding their interplay is crucial for the conservation of biodiversity. Stream fishes in metapopulations are par- ticularly sensitive to habitat fragmentation because per- sistence depends on dispersal and colonization of new habitat but dispersal is constrained to stream networks. Great Plains streams are increasingly fragmented by water diversion and climate change, threatening connectivity of fish populations in this ecosystem. We used seven micro- satellite loci to describe population and landscape genetic patterns across 614 individuals from 12 remaining popu- lations of Arkansas darter (Etheostoma cragini) in Colo- rado, a candidate species for listing under the U.S. Endangered Species Act. We found small effective popu- lation sizes, low levels of genetic diversity within popu- lations, and high levels of genetic structure, especially among basins. Both at- and between-site landscape features were associated with genetic diversity and connectivity, respectively. Available stream habitat and amount of con- tinuous wetted area were positively associated with genetic diversity within a site, while stream distance and inter- mittency were the best predictors of genetic divergence among sites. We found little genetic contribution from historic supplementation efforts, and we provide a set of management recommendations for this species that incor- porate a conservation genetics perspective.

Evaluating the Success of Arkansas Darter Translocations in Colorado: An Occupancy Sampling Approach

AbstractLike many fishes native to western Great Plains streams, the Arkansas darter Etheostoma cragini has declined, apparently in response to changes in flow regimes and habitat fragmentation. We investigated the effectiveness of translocation as a management strategy to conserve this threatened species in the Arkansas River basin of southeastern Colorado. We used a multiscale design to sample the darter and several attributes of its habitat at the local 10‐m site scale, the 3.25‐km translocation segment scale, and the 10‐km riverscape scale in all 19 streams where it had been previously translocated. The darter was captured in 11 of the 19 streams, although 5 were completely dry when visited. Arkansas darters had reproduced in 10 of the 11 streams (one criterion in the state recovery plan), and 6 streams also met a second criterion for abundance (&gt;500 individuals). However, the populations in only two streams unequivocally met a third criterion of being self‐sustaining, because the other four streams had been stocked annually with hatchery‐reared Arkansas darters. We used multistate occupancy estimation, based on two consecutive dipnetting surveys, to determine the habitat characteristics correlated with site occupancy and the detectability of Arkansas darters at the local site scale. The probability of detection for the darter at occupied sites was high for both age‐groups, 92% for age‐0 darters and 75% for age‐1 darters, and was a function of day of year (age 0) and habitat depth (age 1). Cool stream temperature (a site‐scale variable) and sufficient length of available habitat (a riverscape‐scale variable) were the strongest predictors of site occupancy for both age‐groups. The models are useful in identifying new sites for translocations and factors that may place current populations at risk. Effective conservation will require land management practices that conserve, protect, and restore contiguous stream segments with cool temperatures that can sustain Arkansas darters.

The Swimming and Jumping Ability of Three Small Great Plains Fishes: Implications for Fishway Design

AbstractThere is a distinct need for fishway designs that are passable by small‐bodied fishes. Like many lotic systems worldwide, the streams of the North American Great Plains are frequently fragmented by instream structures and other potential migration barriers. This makes small‐bodied fishes of the North American Great Plains appropriate species to use for fishway development. The swimming and jumping abilities of brassy minnow Hybognathus hankinsoni, Arkansas darters Etheostoma cragini, and common shiners Luxilus cornutus, acclimated to water temperatures of 10, 17.5, and 25°C, were quantified in the laboratory. Endurance increased with temperature for brassy minnow but not for the other two species. Based on swimming trial results, current velocities in fishways should not exceed 64 cm/s for brassy minnow or common shiners and 32 cm/s for Arkansas darters. Jumping experiments showed that the presence of a low vertical barrier (5 cm high) dramatically reduced the probability of upstream movement of all three species. Brassy minnow jumped a maximum of 15 cm at 25°C, and common shiners jumped a maximum of 10 cm at 17.5°C. Neither species jumped at 10°C. Arkansas darters did not jump at any temperature. Behavioral observations also indicated that a submerged weir may inhibit the upstream movement of Arkansas darters. Based on the results of this laboratory study, water velocities of less than 0.75 m/s and avoidance of fishways with vertical drops or weir‐type structures will increase the probability of successful passage of small‐bodied fishes.

Summary of Previous and New Records of the Arkansas Darter (Etheostoma cragini) in Arkansas

The Arkansas Darter, Etheostoma cragini, has an extremely limited distribution in Arkansas and is designated as a candidate for listing under the federal Endangered Species Act. It was first documented in the state in 1979 in Wilson Spring near Fayetteville. Between 1979 and 1985 it was collected in 4 additional headwater streams in Benton and Washington counties. A 1997 study documented the persistence of the species in 3 of the 5 historic streams, but 1 stream yielded only a single individual. A 2004-2005 study reassessed the status of the 5 historically known populations and searched broadly for new populations, documenting E. cragini at 15 sites, all within a 2-km radius of historic sites. In 2010-2011, more concentrated sampling efforts were made in the subbasins with prior records of the species. These efforts documented populations at 13 additional sites, greatly improving the resolution of the distribution of this species within Arkansas.

STATUS OF ARKANSAS DARTER, ETHEOSTOMA CRAGINI, AND LEAST DARTER, E. MICROPERCA, IN ARKANSAS

In a 1983 survey of 50 spring-runs in northwestern Arkansas, Etheostoma cragini and E. microperca were each represented by only 5 populations. In summer and autumn 1997, we surveyed localities with historically documented populations and several additional spring-runs for presence of E. cragini and E. microperca to assess the current status of these species in Arkansas. Additionally, we documented local habitat attributes of each sample locality. We estimated population size of persistent populations in our surveys by mark-recapture method. Two populations of E. cragini had 546 (±214) and 79 (±60) individuals, and 2 populations of E. microperca had 1,341 (±349) and 129 (±56) individuals. Both darters inhabited small spring-run habitats with sand and silt substrate and some aquatic vegetation. These species are at risk of extirpation in Arkansas and should be considered for protection.

Dynamics of Intermittent Stream Habitat Regulate Persistence of a Threatened Fish at Multiple Scales

Traditionally, threatened species management has emphasized conservation of individual populations and has assumed that abundance within suitable habitats is primarily governed by local environmental factors. However, recent research has revealed that landscape-level processes such as disturbance, dispersal, and habitat patch mosaic structure may also strongly influence local populations. We studied the population and habitat dynamics of a threatened fish, the Arkansas darter (Etheostoma cragini) at four spatial scales (pool, reach, segment, watershed) in two intermittent Colorado plains streams. At each scale, information on hydrology, habitat, and fish populations was combined to evaluate factors influencing darter persistence. At the pool scale, Arkansas darters persisted in most permanent pools during summer drought, tolerated extremes of hyperthermia and hypoxia, and were extirpated only when pools dried. Deeper pools had a higher probability of persisting during summer drought. At the reach scale, survival measured during an intensive mark–recapture study was high in a stenothermal spring pool, but low in associated downstream pools that froze during winter and had harsh, variable thermal regimes during summer. However, juvenile darters hatched earlier, grew faster, and were relatively more abundant in the warmer downstream pools compared to juveniles in the spring pool, where older fish dominated. Movement rates between the two habitats were relatively low, but adult darters were more mobile, dispersing out of the spring pool in early spring and returning upstream before the onset of summer drought. At the segment scale, flow variation among seasons and years controlled habitat connectivity, thereby affecting dispersal and reproduction and shaping the distribution and age composition of darter populations. At the watershed scale, nonnative northern pike (Esox lucius) preyed on darters, reducing their distribution and abundance in 13 km of Big Sandy Creek and isolating upstream darter populations from those downstream. Large floods scoured new spring-pool refugia and filled other pools, altering the mosaic of physical habitats. A comprehensive picture of factors controlling Arkansas darter populations and their habitat emerged only when physical and biotic processes were integrated across all four scales. To be effective, recovery efforts for species inhabiting variable environments must consider multiple scales, from landscape-level processes that create and maintain refugia to fine-scale factors that regulate the abundance and persistence of local populations.

DYNAMICS OF INTERMITTENT STREAM HABITAT REGULATE PERSISTENCE OF A THREATENED FISH AT MULTIPLE SCALES

Traditionally, threatened species management has emphasized conservation of individual populations and has assumed that abundance within suitable habitats is primarily governed by local environmental factors. However, recent research has revealed that landscape-level processes such as disturbance, dispersal, and habitat patch mosaic structure may also strongly influence local populations. We studied the population and habitat dynamics of a threatened fish, the Arkansas darter (Etheostoma cragini) at four spatial scales (pool, reach, segment, watershed) in two intermittent Colorado plains streams. At each scale, information on hydrology, habitat, and fish populations was combined to evaluate factors influencing darter persistence. At the pool scale, Arkansas darters persisted in most permanent pools during summer drought, tolerated extremes of hyperthermia and hypoxia, and were extirpated only when pools dried. Deeper pools had a higher probability of persisting during summer drought. At the reach scale, s...

Thermal Tolerance and Vegetation Preference of Arkansas Darter and Johnny Darter from Colorado Plains Streams

The Arkansas darter Etheostoma cragini is declining and now occurs in fragmented populations across its former range in the Arkansas River basin from Colorado to Arkansas. Regional surveys indicate that the Arkansas darter primarily inhabits small spring streams with dense aquatic vegetation, suggesting that specific habitat requirements may account for its widespread decline. Thermal tolerance and vegetation preference of the Arkansas darter from the western edge of its range in Colorado were measured in the laboratory and compared with those of the johnny darter E. nigrum, a more abundant habitat generalist from an adjacent basin. Critical thermal maxima of Arkansas darters acclimated to 20, 25, 27.5, and 30°C were higher than those forjohnny darters (35.0–38.4°C versus 34.0–37.4°C). In a modified upper incipient lethal temperature test, Arkansas darters acclimated to 27.5°C all survived 106 h at 30°C when the temperature was raised 1.5°C/h, but almost none survived more than 4 h of exposure to 34 or 36°C. Sixty percent survived 106 h at 32°C. In contrast, all johnny darters died within 17.5 h when exposed to 32°C and within 4.5 h when exposed to 34°C or higher. In behavioral choice trials in aquaria, Arkansas darters selected dense vegetation over open sand 72% of the time, with higher use during day (90%) than night (60%). In contrast, johnny darters showed little preference for vegetation (51% overall). Arkansas darters of the sizes we tested (28–55 mm total length) were able to withstand higher water temperatures than johnny darters (43–67 mm) and many other fishes of Great Plains streams, and they have an innate preference for aquatic vegetation.

Survey of Fishes from Rattlesnake Creek in Central Kansas

We collected 13 species of fishes at 10 sites in Rattlesnake Creek in Edwards, Stafford, and Rice counties, Kansas, during October 1993. In August 1995, a crew from Kansas Department of Wildlife and Parks sampled one site in Stafford County and captured 11 species. Historical collections in this stream included Arkansas darters (Etheostoma cragini), a threatened species in Kansas. None were taken in 1993, but they were captured in 1995. The alluvial aquifer of the lower reach of the stream is in contact with a geological formation that contributes chlorides to the surface water. Chloride values in October 1993 ranged from 10-39 mg/L in the upper portion of the creek to a maximum of 3140 mg/L in the lower reach. Concurrent with this change in water quality, a transition was noted in the fish communities from those dominated by adult red shiners (Cyprinella lutrensis) or juvenile common carp (Cyprinus carpio) in the upper reach to those dominated by adult plains killifish (Fundulus zebrinus) in the lower reach.

Aspects of the Life History of the Stippled Darter Etheostoma punctulatum

Aspects of the life history of the stippled darter Etheostoma punctulatum were studied in the Spring River in SW Missouri. Females attained a maximum standard length of 85 mm and males 83 mm. Both sexes lived slightly more than 4 years. Sparvning began in early February and continued through late May. Males were mature at 1 year of age while only those yearling females at least 49 mm long produced mature ova. Females contained an average of 447 ova2-0.55 mm in diam in two distinct size modes and a group of smaller developing ova. The presence of these distinct size groups of ova throughout the spawning period indicates that two or more clutches of eggs were produced by each mature female. The fertilized eggs were 1.6 mm in diam and hatched in 11 days at 16 C. The diet was made up primarily of crustaceans and aquatic insect larvae. INTRODUCTION The stippled darter Etheostoma punctulatum is a robust darter and the largest in the subgenus Ozarka, reaching 88 mm SL (Kuehne and Barbour, 1983). This darter is distributed throughout the Ozarks where it is most often found in small creeks and spring branches having clear water with permanent flow and silt-free bottoms. Pflieger (1975) indicates it may be found in quiet pools and backwaters where it hides around large rocks or in beds of organic debris. Although not uncommon within its known range of distribution, there are very few populations large enough to permit taking the numbers necessary for life history analysis. Fishes restricted to small headwater streams are frequently subjected to wide fluctuations in environmental conditions. This study was begun with samples being taken in two streams but was terminated in Weaubleau Creek in Hickory Co., Missouri, when dry weather reduced the stream to a few isolated pools and destroyed the darter population. The danger faced by darter populations in headwater locations is also increased by human activity. The second stream location is immediately downstream from a troutrearing facility through which nearly all water in the stream passes. Cleaning of the trout pools in February 1983 produced silt which covered the gravel bottom of the sampling area to a depth of 0.5 m in many places. This site is also 2-km upstream from a well-publicized source of dioxin contamination in the watershed and fishes in the area are known to be concentrating this substance. Activities affecting this stream section may eliminate the desirable habitat which sustains populations of Etheostoma cragini, E. microperca and E. punctulatum among others. Important contributions on life history and ecology of other members of the subgenus Ozarka have been made, but a basic study of the stippled darter has been lacking. Life history features of the threatened paleback darter Etheostoma pallididorsum were determined from preserved museum specimens by Hambrick and Robison (1979). Taber et al. (1986) discussed several aspects of the life history of E. cragini; Boschung (1979) commented on the life history and distribution of E. boschungi, and Etnier (1970) made significant contributions to the known distribution of E. trisella. More recently Ryon (1986) studied the life history and ecology of E. trisella. Information gained by studying the stippled darter is important to the information base which could be used in conservation of this and other less abundant species of its subgenus.

Population Structure, Growth and Reproduction of the Arkansas Darter, Etheostoma cragini (Percidae)

Aspects of the life history of the Arkansas darter were studied in the Spring River of southwest Missouri. Maximum age was 3 years for both sexes but the population was dominated by individuals less than 2 years old. These fish grew rapidly in the first year and both sexes became sexually mature at 1 year or less. Females attained larger sizes and were more numerous than males (1.2:1 respectively). The largest female taken was 63 mm SL; the largest male was 54 mm SL. The spawning period extended from mid-February to mid-July in water that ranged in temperature from 9 to 17°C. Females apparently spawned more than once and average-sized individuals contained 294 to 472 ova > 0.55 mm in diameter from early February through mid-May. The Arkansas darter, Etheostoma cragini, occurs only in the Arkansas River basin from southwest Missouri to central Colorado (Kuehne and Barbour, 1983; Page, 1983). It is apparently rare and declining in the western part of its range (Kuehne and Barbour, 1983; Miller, 1984) but may be locally abundant in northeast Oklahoma and southwest Missouri. The Arkansas darter is a member of the subgenus Ozarka (Williams and Robison, 1980) along with E. boschungi, E. pallididorsum, E. punctulatum and E. trisella.

Fishes of Oklahoma Springs

Fishes of Oklahoma Springs

Distribution, Abundance, and Habitat of the Arkansas Darter Etheostoma cragini (Percidae) in Colorado

Distribution, Abundance, and Habitat of the Arkansas Darter Etheostoma cragini (Percidae) in Colorado