Under the radar: genetic assessment of Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), two Rio Grande basin endemic cyprinids that have experienced recent range contractions

Osborne, Megan J.; Portnoy, David S.; Fields, Andrew T.; Bean, Megan G.; Hoagstrom, Christopher W.; Conway, Kevin W.

doi:10.1007/s10592-020-01328-9

Cited by 9 publications

(7 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…First, our results suggest that long sections of river are likely occupied by a single population, rather than multiple smaller populations with limited genetic connectivity. Tests of isolation by distance among Macrhybopsis fishes have demonstrated high levels of gene flow over broad spatial scales, including Prairie Chub (Ruppel et al 2020), Shoal Chub (Gaughan et al 2019), Speckled Chub (Osborne et al 2021), and potentially Silver Chub (Elbassiouny et al 2023, this special section). This conclusion has implications for assessing conservation redundancy (sensu Wolf et al 2015) because there could be less redundancy if long distances of river and adjoining tributaries are considered as only a single population.…”

Section: Discussionmentioning

confidence: 99%

Why are larger fish farther upstream? Testing multiple hypotheses using Silver Chub in two Midwestern United States riverscapes

Perkin,

Kočovský,

Steffensmeier

et al. 2023

N American J Fish Manag

View full text Add to dashboard Cite

ObjectiveThree competing hypotheses might explain the widely documented intrapopulation larger‐fish‐upstream phenomenon. The age‐phased recruitment hypothesis posits that fish spawn downstream and move upstream as they age and grow, the static population with growth and mortality gradients hypothesis posits that fish spawn throughout a riverscape and growth is greater upstream while recruitment is greater downstream, and the colonization cycle hypothesis posits that fish spawn upstream, larvae drift downstream, and individuals move upstream as they age and grow.MethodsWe tested for the larger‐fish‐upstream pattern using populations of Silver Chub Macrhybopsis storeriana in the Arkansas and Ohio rivers, as well as investigated longitudinal variation in reproductive investment (Arkansas River), age structure for adult fish (Arkansas River), and number and occurrence of age‐0 fish (Ohio River).ResultThe larger‐fish‐upstream pattern was temporally persistent in both riverscapes. In the Arkansas River, reproductive investment was greatest upstream, where initiation of spawning likely occurred based on gonadosomatic indices. Adult fish were most numerous in the Arkansas River 125–175 km upstream from Kaw Reservoir, with age‐2 fish numbers peaking farther upstream compared with age‐1 fish. In the Ohio River, age‐0 fish counts increased downstream and were rare among the shortest river fragments (<100 km) between lock‐and‐dam structures. These findings are inconsistent with the age‐phased recruitment hypothesis based on upstream spawning in the Arkansas River and inconsistent with the static population with growth and mortality gradients hypothesis based on virtual absence of age‐2 fish downstream (Arkansas River) and age‐0 fish upstream (Ohio River). The most likely explanation for longitudinal variation in Silver Chub size distribution is downstream drift of ichthyoplankton followed by net upstream movement (i.e., colonization cycle hypothesis), but formal assessments of movement and ova characteristics require more research.ConclusionManaging multidimensional riverscapes requires insight into the mechanisms that regulate upstream‐to‐downstream patterns in fish populations, and our work underscores a potential size‐related benefit to maintaining broadscale longitudinal connectivity.

show abstract

Section: Discussionmentioning

confidence: 99%

Why are larger fish farther upstream? Testing multiple hypotheses using Silver Chub in two Midwestern United States riverscapes

Perkin,

Kočovský,

Steffensmeier

et al. 2023

N American J Fish Manag

View full text Add to dashboard Cite

show abstract

“…Across the western United States, water abstraction and groundwater pumping threaten many basins (Jaeger et al., 2014; Perkin et al., 2017). Eventually, other rivers in the region such as the Pecos and Canadian may face similar fates as the Rio Grande, both of which contain multiple species of concern (Osborne, Hatt, et al., 2021; Osborne, Portnoy, et al., 2021). For species that are susceptible to stranding, small‐scale local drought refuges will have little benefit to mitigating negative effects of intermittency, and landscape‐scale refuge areas should consider where fish occur before intermittent conditions.…”

Section: Discussionunclassified

“…Eventually, other rivers in the region such as the Pecos and Canadian may face similar fates as the Rio Grande, both of which contain multiple species of concern (Osborne, Hatt, et al, 2021;Osborne, Portnoy, et al, 2021).…”

Section: Conservation Implicationsmentioning

confidence: 99%

Fishes move to transient local refuges, not persistent landscape refuges during river drying experiment

Archdeacon,

Gonzales,

Yackulic

2024

Freshwater Biology

View full text Add to dashboard Cite

Anthropogenically driven flow intermittency is increasing in freshwater streams, with important implications for the management and conservation of aquatic ecosystems. Because most freshwater fishes are mobile, they are expected to emigrate from intermittent reaches, but this may not be true in streams transitioning from perennial to intermittent. Here, we attempt to determine if riverine fishes vacate drying reaches before intermittency or remain in local refuges. We implemented a controlled, in situ experimental flow reduction resulting in intermittency, reducing flows from ~1.0 to 0 m3/s over a 3‐week period. We monitored fish and fish‐habitat changes over a 5‐week period before, during and after flow reductions. During flow reductions, total wetted habitat was ultimately reduced by 91%. Habitat loss over time was not equal among habitat types: pool habitat increased slightly as run habit was lost, and backwater and isolated pool habitats were not strongly related to discharge. Likewise, water depth in run habitats decreased faster than other habitats. Only the river carpsucker Carpiodes carpio appeared to move upstream during flow recession; seven other species remained within drying sites. Habitat loss negatively affected fish populations, but at a lower rate than that at which habitat was lost, until sites dried completely. Overall, two species, red shiner Cyprinella lutrensis and western mosquitofish Gambusia affinis, had increased population growth during the study, whereas the remaining species had population declines. Fishes were able to find transient local refuges during flow reductions but did not vacate sites before intermittent conditions. Accounting for lack of emigration from anthropogenic flow‐intermittent reaches will be important for designing conservation actions for fishes threatened by increasing flow intermittency. Creation of refuge habitats may not be effective for widely dispersed species that do not actively seek refuge habitats, unless those habitats support enough individuals to maintain resilience following the intermittent conditions.

show abstract

“…Second, initiating hatchery supplementation before genetic diversity was affected is crucial to producing genetically diverse offspring. Several other pelagic broadcast-spawning cyprinids in the Great Plains and Chihuahuan Desert of western North America do not yet have captive propagation programs, but they still have considerable genetic diversity (Osborne et al 2021a(Osborne et al , 2021b, making them candidates for a supplementation program that can prevent erosion of genetic diversity. Finally, marking all hatchery fish prior to release, combined with the implementation of sufficient spatial and temporal monitoring to determine the factors controlling recruitment and evaluate the effectiveness of different supplementation strategies, will be critical to initiating a successful supplementation program.…”

Section: Discussionmentioning

confidence: 99%

Hatchery supplementation increases potential spawning stock of Rio Grande Silvery Minnow after population bottlenecks

Archdeacon

Dudley²,

Remshardt

et al. 2023

Trans Am Fish Soc

View full text Add to dashboard Cite

Objective: Supplementation of imperiled wild fish stocks with captively raised fish is a commonly used conservation tool. Programs designed to maintain or improve fish populations through supplementation should be evaluated to determine whether they are meeting conservation objectives. The Rio Grande Silvery Minnow Hybognathus amarus is a small-bodied, endangered minnow endemic to the Rio Grande basin of the southwestern United States. The wild population of Rio Grande Silvery Minnow has been supplemented with captive-reared fish since 2002. Our objective was to determine whether supplementation measurably increases the number of spawning fish after years of population bottlenecks; this objective was simplified because nearly all hatchery-released fish have been given identifying markings. Methods:We leveraged a long-term fish sampling data set (18 years) covering the species' contemporary range and a single-season, high spatial coverage fish sampling data set to determine whether the number of potential spawners was increased by the addition of hatchery fish.Result: Hatchery-reared fish increased the catch rates of spawners by up to an order of magnitude in some years. We also observed that most hatchery-reared fish were recaptured near the point of release. We were able to determine that supplementation with hatchery fish increased the abundance and distribution of Rio Grande Silvery Minnow and provided the desired demographic boost after severe population bottlenecks. Conclusion:Releasing hatchery-reared fish may be a useful tool for conservation of imperiled freshwater fishes. However, there is a need for spawning and rearing infrastructure that matches the life-history of the species and sufficient postrelease monitoring to evaluate the effectiveness of hatchery supplementation. Use of hatchery-reared fish has been beneficial for improving population resiliency of Rio Grande Silvery Minnow following recruitment bottlenecks; however, natural

show abstract

Under the radar: genetic assessment of Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), two Rio Grande basin endemic cyprinids that have experienced recent range contractions

Cited by 9 publications

References 77 publications

Why are larger fish farther upstream? Testing multiple hypotheses using Silver Chub in two Midwestern United States riverscapes

Why are larger fish farther upstream? Testing multiple hypotheses using Silver Chub in two Midwestern United States riverscapes

Fishes move to transient local refuges, not persistent landscape refuges during river drying experiment

Hatchery supplementation increases potential spawning stock of Rio Grande Silvery Minnow after population bottlenecks

Contact Info

Product

Resources

About