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As taxonomic studies revise our understanding of biodiversity, both fisheries managers and the angling public must adapt to best conserve fisheries. Unfortunately, communication gaps between scientists and anglers may result in lags and inaccuracies in the taxonomic information available to anglers. We updated the International Game Fish Association (IGFA)'s black bass Micropterus spp. world records to current taxonomic consensus. Seven new species were acknowledged for all‐tackle world record availability, and four of seven existing species records were revised. Florida Bass M. salmoides (formerly M. floridanus), Neosho Bass M. velox, and four members of the Redeye Bass species complex (M. cahabae, M. chattahoochae, M. tallapoosae, and M. warriorensis) are now recognized. Additionally, Alabama Bass M. henshalli—an emerging invasive species—is now distinguished from the smaller, broadly distributed Spotted Bass M. punctulatus. A misidentified specimen resulted in vacant all‐tackle records for Shoal Bass M. cataractae and Redeye Bass M. coosae. Genetic verification is warranted in the future, but implementation may create accessibility barriers to record submissions. We hope these efforts will encourage anglers to learn more about black bass diversity, to pursue their own world record catches, and to gain awareness of the conservation challenges threatening this iconic group. [ABSTRACT FROM AUTHOR]

Aim: Smallmouth Bass (Micropterus dolomieu; SMB) are globally popular among anglers and have been widely introduced (i.e. stocked) for population management and sportfishing. Importantly, stocking was prevalent before cryptic diversity within the SMB complex was known, which now includes three newly elevated species: Neosho Bass (M. velox; NB), Little River Bass (M. sp. cf. dolomieu Little River; LRB) and Ouachita Bass (M. sp. cf. dolomieu Ouachita River; OB). We sought to quantify population structure and hybridisation and introgression in these three recently described species. Location: Species‐level diversity, particularly in the basin‐restricted LRB and OB in the Ouachita Mountains within the Central Interior Highlands (CIH), North America, suggests the presence of distinct genetic variation that could be eroded by introgression. Methods: We estimated interspecific introgression and intraspecific population differentiation in the Smallmouth Bass species complex (SMB‐C) using 472 specimens comprising SMB, NB, LRB and OB, including the naturally sympatric Spotted Bass (M. punctulatus; SPB). Genomic samples were genotyped on a SNP panel of 192 loci designed to detect allele‐sharing on multiple hierarchical levels. Results: We found low range‐wide hybridisation between species in the SMB‐C and SPB (mostly SMB‐C backcrosses), and interspecific heterozygosity varied, indicating differential introgression. Range‐wide hybridisation between species in the CIH and SMB was similar overall (but mostly F2 and CIH backcrosses) and was observed in streams with known SMB stocking in connected reservoirs. Interspecific heterozygosity in SMB hybrids was also generally lower, indicating later‐generation backcrosses. We found strong population structure in the Ouachita Mountains (LRB and OB). Main Conclusions: Despite isolated incidences of natural (SPB) and human‐mediated (SMB) introgression, genomic identity appears intact in endemic LRB and OB, suggesting potential ecological or behavioural isolating mechanisms preventing cross‐species reproduction. Our findings reveal that genetic variation remains in cryptic, basin‐restricted species in the Ouachita Mountains ecoregion that may be managed for long‐term conservation. [ABSTRACT FROM AUTHOR]

Objective: The Yaqui Catfish Ictalurus pricei, a species that is endemic to the southwestern United States and west‐central Chihuahua and Sonora, Mexico, is extinct in the United States and extremely endangered in Mexico due to habitat loss and hybridization with nonnative Channel Catfish I. punctatus. To re‐establish populations in the United States, a binational program consisting of broodstock collection, fish propagation, stocking, and poststocking monitoring is necessary. This programmatic approach is encapsulated within a Conservation Propagation and Stocking Program (CPSP), which documents important recovery actions, such as genetic management, fish culture, stocking, and poststocking assessments. The focus of our work is to identify the optimal stocking strategy for Yaqui Catfish, thereby informing the framework of a CPSP for the species' recovery. Methods: Our strategy involved simulating population growth using an age‐structured simulation model with varying stocking contribution rates, stocking densities, and stocking frequencies and incorporating these biological data with economic information within a utility function to quantify stocking costs. Result: The optimal strategy requires releasing Yaqui Catfish at a density of 200 fish/ha every 5 years. This strategy excludes natural recruitment because historically, stocked Yaqui Catfish inhabited waters that were either too small or devoid of habitat to induce natural spawning. However, if larger waters or waters having appropriate habitats (e.g., interstitial spaces) are also stocked, it should increase natural recruitment, thereby (1) enabling populations to become self‐sustaining and (2) drastically reducing the reliance on hatcheries for stocking and salvage of declining populations. Conclusion: Our results provide important stocking recommendations within a CPSP, emphasizing the need to build a broodstock before genetically pure Yaqui Catfish disappear. The successful implementation of the optimal stocking strategy requires multiple locations for stocking fish and is contingent on strengthening binational partnerships. This approach fills an important void in Yaqui Catfish reestablishment, helping to prime the successful recovery of this species. Impact statementThe Yaqui Catfish, once native to regions of the United States and Mexico, faces near extinction due to habitat degradation and nonnative hybridization. A binational Conservation Propagation and Stocking Program offers a promising solution, suggesting for the release of 200 fish per hectare every 5 years in the United States. The initiatives success, however, hinges on using multiple stocking locations in Mexico and bolstering binational collaboration. [ABSTRACT FROM AUTHOR]

The Neosho Bass (Micropterus velox), a former subspecies of the keystone top‐predator and globally popular Smallmouth Bass (M. dolomieu), is endemic and narrowly restricted to small, clear streams of the Arkansas River Basin in the Central Interior Highlands (CIH) ecoregion, USA. Previous studies have detected some morphological, genetic, and genomic differentiation between the Neosho and Smallmouth Basses; however, the extent of neutral and adaptive divergence and patterns of intraspecific diversity are poorly understood. Furthermore, lineage diversification has likely been impacted by gene flow in some Neosho populations, which may be due to a combination of natural biogeographic processes and anthropogenic introductions. We assessed: (1) lineage divergence, (2) local directional selection (adaptive divergence), and (3) demographic history among Smallmouth Bass populations in the CIH using population genomic analyses of 50,828 single‐nucleotide polymorphisms (SNPs) obtained through ddRAD‐seq. Neosho and Smallmouth Bass formed monophyletic clades with 100% bootstrap support. We identified two major lineages within each species. We discovered six Neosho Bass populations (two nonadmixed and four admixed) and three nonadmixed Smallmouth Bass populations. We detected 29 SNPs putatively under directional selection in the Neosho range, suggesting populations may be locally adapted. Two populations were admixed via recent asymmetric secondary contact, perhaps after anthropogenic introduction. Two other populations were likely admixed via combinations of ancient and recent processes. These species comprise independently evolving lineages, some having experienced historical and natural admixture. These results may be critical for management of Neosho Bass as a distinct species and may aid in the conservation of other species with complex biogeographic histories. [ABSTRACT FROM AUTHOR]

Angler tag‐return studies are a cornerstone of fisheries research, providing insights into individual movements and estimates of exploitation, among many other applications. However, the data generated from these studies is dependent upon effective communication between anglers and scientists. As technological advances are adopted by anglers, little research has been directed at the potential benefits of incorporating modern tag reporting methods. We tagged stream‐dwelling black bass Micropterus spp. and provided anglers a choice of reporting methods (telephone, email, iNaturalist app, or a "mixed‐mode" combination thereof). Our objectives were to examine the fate of reported fish, quantify trends in data quality across reporting methods, and explore how geographic location and angler avidity may influence use of reporting methods. Ninety‐four percent of tag reports involved the release of the fish with the tag still intact, creating opportunities for longer‐term data collection. Telephone was the most commonly used reporting method; however, this method had significantly lower completeness scores (e.g., lack of photographs or specifying fate of fish) and less precise location information than other methods. In contrast, iNaturalist had the highest completeness and most precise location information but was seldom used and had increased lag times in reporting. We found no significant differences in the proportion of reporting methods used across stream locations in our study, and avid anglers appeared to be individualistic in their choice of method. Overall, our study suggests that the adoption of modern reporting methods, like email and smartphone apps, could benefit data collection efforts of angler tag‐return studies. Fisheries scientists may wish to consider which reporting methods align with their specific study objectives and with the angling public of a given study area. [ABSTRACT FROM AUTHOR]

The Yaqui Catfish Ictalurus pricei is an understudied species, with limited information available on its ecology, distribution, and local habitat use. Native to the southwestern United States and northwestern Mexico, Yaqui Catfish populations are declining, which has prompted listing of the species as threatened in the United States and as a species of concern in Mexico. Water overallocation, habitat degradation, invasive species introductions, and hybridization with nonnative Channel Catfish I. punctatus have caused the populations in Mexico to decline. The United States population collapsed after years of low recruitment. To better focus conservation efforts as well as define habitat associated with Yaqui Catfish occurrences, we assessed the distribution in the Yaqui River basin of Mexico by using historical data at a landscape scale. Yaqui Catfish were historically found across the watershed among a diversity of environments but were most frequently associated with small, intermittent streams. Basin land cover was dominated by forest, shrubland, and grassland, and Yaqui Catfish generally occurred in stream segments at similar proportions. However, a small number of Yaqui Catfish occurrences were associated with urban and cropland land cover types in proportions greater than the availability of those categories on the landscape. With the species facing declines in the region, this work will help to inform future conservation efforts aimed at securing the Yaqui Catfish, protecting suitable habitat, and better defining its current status in Mexico. [ABSTRACT FROM AUTHOR]

Water temperature is an important abiotic factor that impacts physiological processes in fish. Attempts to quantify thermal tolerance of fishes exposed to various temperatures have been performed since the 1800s. A common approach to test the thermal tolerance of fishes is the critical thermal method. Traditionally this method has required access to large and expensive lab equipment. However, many individuals may not have direct access to such equipment, making critical thermal studies difficult‐to‐impossible to conduct. We present a simple and cost‐friendly alternative device to use for critical thermal minima trials. This device uses a cooler with a copper line and copper coil to chill water within an aquarium. A pump and valves control the water flow as it passes from the aquarium through the copper. This allows the user to lower the water temperature in the aquarium from 28oC to 0oC at a steady rate of 0.23oC min−1. The device allows those with limited funding or without access to traditional lab equipment the ability to perform critical thermal minima trials, expanding our collective understanding of life histories of fish and their potential vulnerabilities to increasingly altered thermal environments. [ABSTRACT FROM AUTHOR]

Summary: Water temperature controls a plethora of morphological and metabolic functions in fishes and studies examining thermal tolerance of fishes and the responses of fishes to changing water temperatures have been conducted for over a century. Although there has been a renewed interest in the management and conservation of alligator gar, currently there are no data regarding the thermal minima of the species. In this study, we obtained alligator gar juveniles from a hatchery setting, acclimated these fish to three separate water temperatures (21, 24.5, and 28°C) and then subjected them to critical thermal minima trials to quantify lower thermal tolerance. Critical thermal minima results were found to be related with acclimation temperature and total length. Less developed gar experienced equilibrium loss at higher temperatures than larger, more developed gar. Also, alligator gar in the coldest acclimation trials (21°C) were able to tolerate the lowest temperatures. The mean CTmin temperature values obtained for each acclimation trial were 11.57°C, SD = 1.39 (21°C), 12.83°C, SD = 1.47 (24.5°C), and 14.16°C, SD = 1.60 (28°C). This study helps to fill an important data gap in alligator gar life history, and our results could be beneficial for management of alligator gar and determining potential future range distributions. [ABSTRACT FROM AUTHOR]

Fishing in streams and rivers is a popular outdoor recreation activity in eastern Oklahoma, where most anglers target black bass (Micropterus) species. Since the early 1990s, when the last assessment of black bass fishing in the region was conducted, broadscale factors such as harvesting behavior, state fishery regulations, and bass population dynamics have changed. In 2018, we conducted creel and fish tagging surveys in three tributaries of Lake Tenkiller (Caney Creek, Baron Fork, and Illinois River) that differed in size and accessibility to provide current estimates of catch, harvest, and effort directed toward black bass. We then related these estimates to angler socioeconomic characteristics. The amount of angler effort was concomitant with stream size and accessibility, being greatest in the largest stream with the most access (Illinois River). However, catch rates were highest in the medium‐sized stream (Baron Fork). Harvest rates and exploitation were near zero in all systems. Anglers fishing Caney Creek, the smallest and least accessible stream, were nearly all local, coming from zip codes ~42 km away, with low median household incomes compared to anglers at the other streams who came from a broader array of more distant zip codes and had higher median household incomes. Anglers fishing the smallest stream were also more interested in harvesting fish and having higher creel limits than anglers at the other two systems. In the Oklahoma Ozark Highlands, stream size and accessibility appear to be a significant factor in angler demographics, potentially necessitating different management strategies. [ABSTRACT FROM AUTHOR]

The Alligator Gar Atractosteus spatula (AG) is a long‐lived fish of growing management and conservation interest. Situated on the border of Texas and Oklahoma, Lake Texoma supports one of the last robust AG populations in Oklahoma; however, a genetic evaluation of this population is lacking. We genotyped AG individuals with 17 microsatellite loci, 7 of which also cross‐amplified in three sympatric Lepisosteus species: the Longnose Gar L. osseus (LN), Shortnose Gar L. platostomus (SN), and Spotted Gar L. oculatus (SP). Bayesian assignment analyses conducted in STRUCTURE and NewHybrids confirmed that a field‐identified hybrid was an F1 AG × LN and identified five other individuals that were suspected backcrosses (three LN × SN; two SN × SP). Alligator Gar had the lowest observed heterozygosity (0.179) and the lowest allelic richness (1.682) among the nonhybrid individuals of the four gar species examined. We also examined the potential for population structure and differences in pairwise relatedness (r) between two areas where AG are commonly encountered within Lake Texoma: the Red River and Washita River arms. No population structure was detected using noninformative or location priors in STRUCTURE, and estimates of r produced by the TrioML estimator in COANCESTRY were not significantly different between arms (overall mean r = 0.199). Point estimates of effective population size ranging from 16.3 to 29.2 suggested that the AG population may be vulnerable to the effects of inbreeding depression and random genetic drift. Results provide a genetic status assessment of AG in Lake Texoma and a baseline for future management and conservation decisions within Lake Texoma and surrounding regions. [ABSTRACT FROM AUTHOR]

Leveraging existing presence records and geospatial datasets, species distribution modeling has been widely applied to informing species conservation and restoration efforts. Maxent is one of the most popular modeling algorithms, yet recent research has demonstrated Maxent models are vulnerable to prediction errors related to spatial sampling bias and model complexity. Despite elevated rates of biodiversity imperilment in stream ecosystems, the application of Maxent models to stream networks has lagged, as has the availability of tools to address potential sources of error and calculate model evaluation metrics when modeling in nonraster environments (such as stream networks). Herein, we use Maxent and customized R code to estimate the potential distribution of paddlefish (Polyodon spathula) at a stream‐segment level within the Arkansas River basin, USA, while accounting for potential spatial sampling bias and model complexity. Filtering the presence data appeared to adequately remove an eastward, large‐river sampling bias that was evident within the unfiltered presence dataset. In particular, our novel riverscape filter provided a repeatable means of obtaining a relatively even coverage of presence data among watersheds and streams of varying sizes. The greatest differences in estimated distributions were observed among models constructed with default versus AICC‐selected parameterization. Although all models had similarly high performance and evaluation metrics, the AICC‐selected models were more inclusive of westward‐situated and smaller, headwater streams. Overall, our results solidified the importance of accounting for model complexity and spatial sampling bias in SDMs constructed within stream networks and provided a roadmap for future paddlefish restoration efforts in the study area. [ABSTRACT FROM AUTHOR]

Black bass Micropterus spp. are quintessential North American sportfishes that support economically valuable fisheries and act as keystone predators within aquatic ecosystems. Despite their prominence among North American fish fauna, a number of taxonomic designations are unresolved and novel forms continue to be identified within drainages of the southeastern USA. We review the current understanding of black bass diversity, including distributions, evolutionary histories, and phylogenetic relationships. We also provide a brief overview of the major paradigms that have been applied to black bass management and highlight an emerging focus on the conservation of black bass diversity. Black bass diversity is threatened by anthropogenic land and water use, fragmentation of fluvial habitats, historic and contemporary stocking of non‐native congeners, and climate change. Successful conservation of black bass diversity requires that management agencies prioritize the protection of native species, forms, and lineages within and across jurisdictional boundaries. Collaboration among scientists and resource managers is needed to develop practical ways to ameliorate current problems created by past and present anthropogenic alterations, while also preparing for future challenges like global climate change. [ABSTRACT FROM AUTHOR]

As the use of social media becomes more common among fisheries scientists and resource managers, case studies of ongoing outreach efforts can provide insights on how to increase the effectiveness of such programs. Herein, we summarize efforts to engage anglers and the general public with outreach messages related to black bass Micropterus spp. diversity and conservation via the Black Bass Conservation Committee's Facebook page. Specifically, we detail how we continue to build our audience, generate impactful content, and facilitate engagement and interactions with our audience. We end with some lessons learned while running this social media outreach page and discuss the outlook of these efforts, including opportunities to integrate citizen science. [ABSTRACT FROM AUTHOR]

The need to assess agreement exists in various clinical studies where quantifying inter‐rater reliability is of great importance. Use of unscaled agreement indices, such as total deviation index and coverage probability (CP), is recommended for two main reasons: (i) they are intuitive in a sense that interpretations are tied to the original measurement unit; (ii) practitioners can readily determine whether the agreement is satisfactory by directly comparing the value of the index to a prespecified tolerable CP or absolute difference. However, the unscaled indices were only defined in the context of comparing two raters or multiple raters that assume homogeneity of variances across raters. In this paper, we introduce a set of overall indices based on the root mean square of pairwise differences that are unscaled and can be used to evaluate agreement among multiple raters that often exhibit heterogeneous measurement processes in practice. Furthermore, we propose another overall agreement index based on the root mean square of pairwise differences that is scaled and extends the concept of the recently proposed relative area under CP curve in the presence of multiple raters. We present the definitions of overall indices and propose inference procedures in which bootstrap methods are used for the estimation of standard errors. We assess the performance of the proposed approach and demonstrate its superiority over the existing methods when raters exhibit heterogeneous measurement processes using simulation studies. Finally, we demonstrate the application of our methods using a renal study. [ABSTRACT FROM AUTHOR]

The Neosho Smallmouth Bass Micropterus dolomieu velox is endemic to Arkansas River tributaries originating in the Ozark Highlands and Boston Mountains. Although morphologically and genetically distinct from other populations of Smallmouth Bass M. dolomieu, the conservation‐genetic status of Neosho Smallmouth Bass is largely unknown. To assist in filling this data gap, we quantified introgressive hybridization, genetic diversity, and population structure of Neosho Smallmouth Bass in two major river basins (Grand River and Illinois River) using seven polymorphic microsatellite markers. Introgressive hybridization with stocked Tennessee lake‐strain Smallmouth Bass was most prevalent in the Illinois River, wherein the overall genomic proportion of Neosho Smallmouth Bass alleles was only 0.422. After accounting for hybrid individuals, genetic diversity of Neosho Smallmouth Bass was generally higher in larger rivers and lower in smaller, isolated streams. Three distinct population clusters were identified at the uppermost level of genetic structure—one from the Illinois River basin and two from the Grand River basin. These three population boundaries accounted for approximately 7% of the hierarchical genetic variation within our data set, and substructure below the uppermost level accounted for an additional 2% of genetic variation. The population structure we discovered can provide a blueprint for management that conserves diversity within and among populations; for example, population boundaries can be used to determine brood source locations for supplemental stocking efforts to counter nonnative introgression. Introgressive hybridization with nonnative Smallmouth Bass appears to be the most pertinent threat to the Neosho Smallmouth Bass subspecies, which is of conservation value to the overall adaptability of Smallmouth Bass as a species. [ABSTRACT FROM AUTHOR]

Abstract: Endemic to the Apalachicola River basin of the southeastern USA, the Shoal Bass Micropterus cataractae is a fluvial‐specialist sport fish that is imperiled because of anthropogenic habitat alteration. To counter population declines, restorative stocking efforts are becoming an increasingly relevant management strategy. However, population genetic structure within the species is currently unknown, but it could influence management decisions, such as brood source location. Leveraging a collaborative effort to collect and genotype specimens with 16 microsatellite loci, our objective was to characterize hierarchical population structure and genetic differentiation of the Shoal Bass across its native range, including an examination of structuring mechanisms, such as relatedness and inbreeding levels. Specimens identified as Shoal Bass were collected from 13 distinct sites (N ranged from 17 to 209 per location) and were then taxonomically screened to remove nonnative congeners and hybrids (pure Shoal Bass N ranged from 13 to 183 per location). Our results revealed appreciable population structure, with five distinct Shoal Bass populations identifiable at the uppermost hierarchical level that generally corresponded with natural geographic features and anthropogenic barriers. Substructure was recovered within several of these populations, wherein differences appeared related to spatial isolation and local population dynamics. An analysis of molecular variance revealed that 3.6% of the variation in our data set was accounted for among three larger river drainages, but substructure within each river drainage also explained an additional 8.9% of genetic variation, demonstrating that management at a scale lower than the river drainage level would likely best conserve genetic diversity. Results provide a population genetic framework that can inform future management decisions, such as brood source location, so that genetic diversity within and among populations is conserved and overall adaptability of the species is maintained. [ABSTRACT FROM AUTHOR]

Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial-specialist shoal bass ( Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non-native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non-native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non-native congeners, wherein non-natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free-flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats. [ABSTRACT FROM AUTHOR]

The reaction of an aminopolycarboxylate ligand, aspartic- N-monoacetic acid (ASMA), with [Re(CO)3(H2O)3]+ was examined. The tridentate coordination of ASMA to this ReI(CO)3 precursor yielded fac-Re(CO)3(ASMA) as a mixture of diastereomers. The chemistry is analogous to that of the TcI(CO)3 complex, which yields fac-99mTc(CO)3(ASMA) under similar conditions. The formation, structure, and isomerization of fac-Re(CO)3(ASMA) products were characterized by HPLC, 1H NMR spectroscopy, and X-ray crystallography. The two major fac-Re(CO)3(ASMA) diastereomeric products each have a linear ONO coordination mode with two adjacent five-membered chelate rings, but they differ in the endo or exo orientation of the uncoordinated acetate group, in agreement with expectations based on previous studies. Conditions have been identified for the expedient isomerization of fac-Re(CO)3(ASMA) to a mixture consisting primarily of one major product. Because different isomeric species typically have different pharmacokinetic characteristics, these conditions may prove useful for the practical isolation of a single 99mTc(CO)3(ASMA) species, thus allowing the isolation of the isomer that has optimal imaging and pharmacokinetic characteristics. This information will aid in the design of future 99mTc radiopharmaceuticals. [ABSTRACT FROM AUTHOR]