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Black carp (Mylopharyngodon piceus), a large molluscivorous cyprinid native to eastern Asia, has become established in the Mississippi River basin in North America. The vulnerability of most North American snails and bivalves to black carp predation remains unknown, especially as it relates to juvenile black carp transitioning to mollusk prey. We conducted feeding experiments to assess the relative vulnerability of different mollusks to predation by age-0 and age-1 black carp. Age-0 black carp were tested with the North American native unionid Hamiota perovalis, a native pleurocerid snail Elimia livescens, and a native physid snail in the genus Physella. Age-1 black carp were tested with Elimia livescens, the North American native unionids Lampsilis cardium and Lampsilis cariosa, a native sphaeriid clam in the genus Musculium, and the non-native cyrenid clam Corbicula fluminea. Juvenile black carp readily attacked and consumed mollusks, but differences in vulnerability were evident among prey taxa exposed to age-0 and age-1 black carp. Age-0 black carp were able to consume Physella approaching the extent of their mouth gape. Age-1 black carp displayed greater feeding capabilities than age-0 black carp and easily consumed Elimia, Lampsilis, and Musculium. The only prey taxon that age-1 black carp struggled to consume was Corbicula, which had the thickest and widest shells relative to predator gape of all prey tested. Our results suggest that a wide range of small or juvenile mollusks are susceptible to predation by juvenile black carp but highlight that prey-specific characteristics, such as shell strength and shell size, may drive differential predation pressure on mollusk populations as the invaded range of black carp expands.

Invasive bivalves continue to spread and negatively impact freshwater ecosystems worldwide. As different metrics for body size and biomass are frequently used within the literature to standardise bivalve-related ecological impacts (e.g. respiration and filtration rates), the lack of broadly applicable conversion equations currently hinders reliable comparison across bivalve populations. To facilitate improved comparative assessment among studies originating from disparate geographical locations, we report body size and biomass conversion equations for six invasive freshwater bivalves (or species complex members) worldwide: Corbicula fluminea, C. largillierti, Dreissena bugensis, D. polymorpha, Limnoperna fortunei and Sinanodonta woodiana, and tested the reliability (i.e. precision and accuracy) of these equations. Body size (length, width and height) and biomass metrics of living-weight (LW), wet-weight (WW), dry-weight (DW), dry shell-weight (SW), shell free dry-weight (SFDW) and ash-free dry-weight (AFDW) were collected from a total of 44 bivalve populations located in Asia, the Americas and Europe. Relationships between body size and individual biomass metrics, as well as proportional weight-to-weight conversion factors, were determined. For most species, although inherent variation existed between sampled populations, body size directional measurements were found to be good predictors of all biomass metrics (e.g. length to LW, WW, SW or DW: R2 = 0.82–0.96), with moderate to high accuracy for mean absolute error (MAE): ±9.14%–24.19%. Similarly, narrow 95% confidence limits and low MAE were observed for most proportional biomass relationships, indicating high reliability for the calculated conversion factors (e.g. LW to AFDW; CI range: 0.7–2.0, MAE: ±0.7%–2.0%). Synthesis and applications. Our derived biomass prediction equations can be used to rapidly estimate the biologically active biomass of the assessed species, based on simpler biomass or body size measurements for a wide range of situations globally. This allows for the calculation of approximate average indicators that, when combined with density data, can be used to estimate biomass per geographical unit-area and contribute to quantification of population-level effects. These general equations will support meta-analyses, and allow for comparative assessment of historic and contemporary data. Overall, these equations will enable conservation managers to better understand and predict ecological impacts of these bivalves. Fil: Coughlan, Neil E.. The Queens University of Belfast; Irlanda. University College Cork; Irlanda Fil: Cunningham, Eoghan M.. The Queens University of Belfast; Irlanda Fil: Cuthbert, Ross N.. The Queens University of Belfast; Irlanda. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania Fil: Joyce, Patrick W. S.. The Queens University of Belfast; Irlanda Fil: Anastácio, Pedro. Universidade de Évora; Portugal Fil: Banha, Filipe. Universidade de Évora; Portugal Fil: Bonel, Nicolás. Université Montpellier II; Francia. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Bradbeer, Stephanie J.. University of Leeds; Reino Unido Fil: Briski, Elizabeta. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania Fil: Butitta, Vince L.. University of Wisconsin; Estados Unidos Fil: Cadková, Zuzana. Czech University of Life Sciences; República Checa Fil: Dick, Jaimie T. A.. The Queens University of Belfast; Irlanda Fil: Douda, Karel. Czech University of Life Sciences; República Checa Fil: Eagling, Lawrence E.. The Queens University of Belfast; Irlanda Fil: Ferreira Rodríguez, Noé. Universidad de Vigo; España Fil: Hünicken, Leandro Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Johansson, Mattias L.. University of North Georgia; Estados Unidos Fil: Kregting, Louise. The Queens University of Belfast; Irlanda Fil: Labecka, Anna Maria. Jagiellonian University; Polonia Fil: Li, Deliang. Hunan Agricultural University; China Fil: Liquin, Florencia Fernanda. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina Fil: Marescaux, Jonathan. University of Namur; Bélgica. e-biom; Bélgica Fil: Morris, Todd J.. Fisheries and Ocean Canada; Canadá Fil: Nowakowska, Patrycja. University of Gdansk; Polonia Fil: Ozgo, Malgorzata. Kazimierz Wielki University; Polonia Fil: Paolucci, Esteban Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Peribáñez, Miguel A.. Universidad de Zaragoza; España Fil: Riccardi, Nicoletta. Consiglio Nazionale delle Ricerche; Italia Fil: Smith, Emily R. C.. University College London; Estados Unidos Fil: Sylvester, Francisco. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina

Before this study, researchers had not systematically surveyed the Rio Conchos, a tributary of the Rio Grande located in northern Mexico, for freshwater mussels. The Texas hornshell, Popenaias popeii, an endangered species under the United States Endangered Species Act, occurs in the main stem of the Rio Grande near its confluence with the Rio Conchos. The Texas hornshell's proximity to the Rio Conchos prompted us to survey to determine whether P. popeii also occurs within the Conchos basin. Additionally, previous researchers described the Conchos disk, Disconaias conchos, from the Rio Conchos but, to date, no one has reported live individuals of this species. The goal of this study was to determine the status of mussels within the Rio Conchos basin and to provide a baseline for future monitoring efforts. We qualitatively surveyed 11 sites within the Rio Conchos basin in May 2018. In total, we found two live individuals of the paper pondshell, Utterbackia imbecillis, at one site in the Rio San Pedro, a tributary of the Conchos River, and as shells of recently live individuals at two sites in the Rio Conchos. We found D. conchos as relict shells only at three sites, two in the Rio Conchos and one in a tributary of the river at Coyame. The lack of live or fresh-dead material suggests that D. conchos is extinct. We also found live individuals of nonnative Asian clams (Corbicula spp.) at 10 sites. Sand and gravel mining, high organic pollution, and inadequate instream flows were evident throughout the basin and might explain the general absence of mussels.

Understanding a species' historical and current distribution is critical when making conservation and management decisions. Recent observations in headwater streams of northern Illinois, USA, where no previous records of Iowa Darters Etheostoma exile occurred, revealed the need to re-evaluate its state-wide distribution. We conducted a series of species distribution modelling procedures coupled with targeted field surveys to generate historical and contemporary distribution models. The historical distribution model indicated E. exile distributions were concentrated across extreme northern Illinois. Both contemporary models included results of the historical model as a model variable. Based on the initial contemporary model, 30 potential Iowa Darter sites, 10 each of three groups representing low, medium and high model scores, were sampled during the summer of 2016. Field surveys provided nine new E. exile localities and presence-absence data from field surveys were then applied to revise the contemporary model. The revised contemporary model suggests a decrease in certain areas of its historic Illinois range, as well as areas where it has potentially expanded its range.

The distribution of the Illinois state-threatened Banded Killifish Fundulus diaphanus has remained largely unchanged in Illinois from 1880 to 2000, being restricted mainly to the northeastern corner of the state. One population identified as Western Banded Killifish F. d. menona has remained stable in the glacial lakes region along the southeastern Wisconsin–northeastern Illinois border. Starting in 2001 a second population began to spread and become more common along the Lake Michigan shoreline. From there the population expanded through the Chicago Area Waterway System into the Des Plaines River and eventually the Illinois River. Historical museum specimens from this region are identified as F. d. menona, but recent specimens are identified as hybrids between F. d. menona and Eastern Banded Killifish F. d. diaphanus. Subsequently, a third population appeared in the Mississippi River near the mouth of the Rock River in 2009 and has spread from there. These individuals are also identified as F. d. menona. The rapid expansion of Banded Killifish from Lake Michigan to the Illinois River appears to be an invasion of the Eastern subspecies F. d. diaphanus and the subsequent hybridization with the native Western subspecies. It is unknown where the Banded Killifish in the Mississippi River originated, possibly from populations 160 kilometers upstream or human introductions. As the Illinois River and Mississippi River populations continue to expand their ranges, their ecological impacts are unknown at this time.

Benthic macroinvertebrates were washed from nearly 1000 federally endangered freshwater mussels that had been collected from Pennsylvania during a reintroduction project to 2 eastern Illinois streams. Most benthic macroinvertebrates collected were larvae of the Neophylax fuscus, but other caddisflies and segmented worms were also observed. No unoccupied caddisfly cases were observed on live mussels, leaving open the question as to the seasonal fate of these microhabitats after caddisflies pupate and emerge in the Autumn of each year. Unionid mussel shells might modify local-scale species diversity by influencing physical and hydrau lic properties of microhabitats.

Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for freshwater mussel conservation assessment. To address these topics, we group research priorities into two categories: intrinsic or extrinsic factors. Intrinsic factors are indicators of organismal or population status, while extrinsic factors encompass environmental variables and threats. An understanding of intrinsic factors is useful in monitoring, and of extrinsic factors are important to understand ongoing and potential impacts on conservation status. This dual approach can guide conservation status assessments prior to the establishment of priority species and implementation of conservation management actions., La lista completa de autores de este trabajo puede verse en el archivo asociado., Facultad de Ciencias Naturales y Museo

Lithasia armigera (Armored Rocksnail) historically occurred in the Cumberland, Ohio, and Tennessee river drainages of eastern North America, whereas Lithasia verrucosa (Verrucose Rocksnail) is known from the Ohio, Tennessee, and Black river drainages. Prior to our 24–27 September 2012 surveys, neither species had been recorded from the Mississippi River. We discovered Armored Rocksnail near the Mississippi River-Missouri River confluence in the St. Louis metropolitan area, and both Armored Rocksnail and Verrucose Rocksnail 5 linear miles east-northeast of Osceola, AR.

This is the first American Fisheries Society conservation assessment of freshwater gastropods (snails) from Canada and the United States by the Gastropod Subcommittee (Endangered Species Committee). This review covers 703 species representing 16 families and 93 genera, of which 67 species are considered extinct, or possibly extinct, 278 are endangered, 102 are threatened, 73 are vulnerable, 157 are currently stable, and 26 species have uncertain taxonomic status. Of the entire fauna, 74% of gastropods are imperiled (vulnerable, threatened, endangered) or extinct, which exceeds imperilment levels in fishes (39%) and crayfishes (48%) but is similar to that of mussels (72%). Comparison of modern to background extinction rates reveals that gastropods have the highest modern extinction rate yet observed, 9,539 times greater than background rates. Gastropods are highly susceptible to habitat loss and degradation, particularly narrow endemics restricted to a single spring or short stream reaches. Compil...

During a pilot survey, sponges and mollusks were sampled from the bottom of the middle Xingu River (rapids) and lower Xingu River (ria) via hand-picking in shallows and trawling and surface-supplied dives in deeper waters. The survey revealed a benthic community composed of eight sponge species in four genera and three families, and added six species to the Xingu Basin fauna. Sponges exhibited distinct variation in body shape corresponding to local environmental conditions such as water depth, current velocity and available substrates. Sponges inhabiting rocky bottoms in swift currents (rapids) typically formed crusts. Those in the deeper, calmer waters of the ria attained massive and elaborate forms while attached to infaunal bivalves. Oncosclera navicella and Drulia cristata exhibited crusts and massive forms as adaptations to rapids and ria, respectively. In the middle to lower Xingu, sponges encrusted the shells of eleven species of bivalves (seven infaunal, three epifaunal, and one infaunal/epifaunal) and one infaunal/epifaunal gastropod. Bivalves provide key substrates for supporting sponges above the sand, mud and detritus of the Xingu ria. Potential impacts of the Belo Monte Dam complex on the sponge fauna of the middle Xingu rapids are discussed.

We report on a recently discovered population of the freshwater snail Lithasia geniculata (Ornate Rocksnail) (Gastropoda: Pleuroceridae) from the Ohio River, IL, the first documented occurrence for this species outside the Tennessee and Cumberland river basins. We collected 14 individuals on 26–27 August 2008 from the Ohio River, near Mound City, Pulaski County, IL. All of the specimens collected were discovered on an exposed shoal after the river dropped ≈0,5 min a 24-hr period and had several (7–33) Dreissena polymorpha (Zebra Mussel) attached to their shells.

Freshwater mussels were sampled in the upper Mackinaw River basin, Illinois, for five years to determine if a single, one-hour visit was enough to adequately characterize the species richness at a headwater stream site when using the timed search technique. Eight sites were each handpicked for one person-hour every year, and species richness was calculated to determine if it varied by year for five years. During 39 person-hours, 2,692 live individuals of 14 species were collected. Species accumulation curves and Spearman's correlation analysis suggested that a single, one-hour visit was not adequate when using the timed search technique to determine species richness in headwater streams of the Mackinaw River basin and might not be sufficient in other basins.

Aquatic snails (Gastropoda) are a vital component of stream ecosystems. Not only do they act as biological indicators of stream integrity (Lydeard et al. 2004), but they also occupy a pivotal position in stream food web dynamics by grazing on periphyton and serving as a food source for many predators (Stewart 2006). However, freshwater mollusks, including gastropods, are one of the most imperiled groups of animals in North America, primarily as the result of habitat destruction (Lydeard et al. 2004). Despite sufficient evidence that aquatic snails are ecologically important, scientists have a poor understanding of the geographic distribution, environmental requirements, and even systematic classification of these imperiled species (Graf 2001; Stewart 2006).

We sampled 9 sites (5 free-flowing and 4 impounded) to investigate effects of lowhead dams on the habitat characteristics and the freshwater mussel assemblage of the Fox River in Illinois. We used 2 habitat indices, the Qualitative Habitat Evaluation Index (QHEI) and the Stream Habitat Assessment Protocol (SHAP), to determine effects of lowhead dams on habitat quality. Free-flowing sites had higher QHEI and SHAP scores than impounded sites, indicating higher quality stream habitat. We calculated 3 variables, catch-per-unit-effort (CPUE), extant spe- cies richness, and percent missing species, to establish effects of lowhead dams on freshwater mussels. Free-flowing sites had higher CPUE and extant species richness and lower percent missing species than impounded sites. We also examined literature reviews and museum collection holdings to determine species distributions within the basin. These data suggest that dams limit the upstream distribution of 5 species.

Little is known about the life history and habits, including the reproductive behavior, of Pimephales tenellus. I collected 182 individuals and transferred them into 10 aquaria; of these fish, 18 pairs spawned. Based on my aquarium observations, P. tenellus exhibited the egg-clustering strategy similar to the other species of Pimephales.

Sixty years have past since the last extensive freshwater mussel (Bivalvia: Unionidae) survey of the Wakarusa River basin. During that time, the basin has experienced substantial changes, including construction of a reservoir. To determine what changes might have occurred in the freshwater mussel assemblage since the last survey, I sampled freshwater mussels by hand grabbing in a haphazard manner at 28 sites in the summer of 2004. Of the 27 species historically known from the basin, I collected 39 live individuals representing nine species in 52 man-hours, including one Truncilla donaciformis, which is listed as species-in-need-of-conservation by the state of Kansas; I also found valves of an additional four species. Six sites had live individuals, and valves were found at an additional ten sites. I did not find the exotic Dreissena polymorpha, which recently has become established in Kansas in the Walnut River basin.

The hypothesis that temperate stream fishes alter habitat use in response to changing water temperature and stream discharge was evaluated over a 1 year period in the Neosho River, Kansas, U.S.A. at two spatial scales. Winter patterns differed from those of all other seasons, with shallower water used less frequently, and low-flow habitat more frequently, than at other times. Non-random habitat use was more frequent at the point scale (4·5 m 2 ) than at the larger reach scale (20-40 m), although patterns at both scales were similar. Relative to available habitats, assemblages used shallower, swifter-flowing water as temperature increased, and shallower, slower-flowing water as river discharge increased. River discharge had a stronger effect on assemblage habitat use than water temperature. Proportion of juveniles in the assemblage did not have a significant effect. This study suggests that many riverine fishes shift habitats in response to changing environmental conditions, and supports, at the assemblage level, the paradigm of lotic fishes switching from shallower, high-velocity habitats in summer to deeper, low-velocity habitats in winter, and of using shallower, low-velocity habitats during periods of high discharge. Results also indicate that different species within temperate river fish assemblages show similar habitat use patterns at multiple scales in response to environmental gradients, but that non-random use of available habitats is more frequent at small scales.

We assessed the effects of lowhead dams on the EPT group (ephemeropterans, plecopterans, and trichopterans) by sampling habitat and macroinvertebiates monthly from November 2000 to October 2001 at eight gravel bars centered around two lowhead dams on the Neosho River, Lyon County, Kansas. Sites included a reference and treatment site upstream and downstream from each dam. Percent EFT was greater at reference sites than upstream treatment sites, and was positively correlated with stream velocity and %gravel in the substrate, but negatively correlated with substrate compaction and %boulder in the substrate. These results are similar to those for large dams and suggest that differences in habitat around these lowhead dams are unfavorable for EPT taxa, a finding important to the conservation and restoration of biotic integrity in riverine ecosystems.

We studied spatiotemporal patterns of fish assemblage structure in the Neosho River, Kansas, a system impounded by low-head dams. Spatial variation in the fish assemblage was related to the location of dams that created alternating lotic and lentic stream reaches with differing fish assemblages. At upstream sites close to dams, assemblages were characterized by species associated with deeper, slower-flowing habitat. Assemblages at sites immediately downstream from dams had higher abundance of species common to shallow, swift-flowing habitat. Temporal variation in assemblage structure was stronger than spatial variation, and was associated with fish life history events such as spawning and recruitment, as well as seasonal changes in environmental conditions. Our results suggest that low-head dams can influence spatial patterns of fish assemblage structure in systems such as the Neosho River and that such assemblages also vary seasonally.

Anthropogenic disturbances to streams have been shown to cause channel instability resulting in increased sedimentation and altered substrate composition. I studied effects of two such disturbances (logging and bridge construction) on habitat among three phases (pre-, during-, and post-disturbance) for two southern Jefferson County (Kansas) intermittent streams. From autumn 2001 to spring 2004, I seasonally sampled six habitat variables (thalweg depth, bank full width, percent bank exposed, riparian thickness, geometic mean, and substrate compaction) along 100 m benchmarks upstream from, at the site of, and downstream from disturbance locations. Using repeated-measure analysis of variance with a sequential Bonferroni correction of a = 0.05 and Tukey's studentized range test for pairwise comparisons, all six variables differed significantly at both the logging location and the bridge construction location among phases, whereas no variables differed significantly upstream from or downstream from ei...

Many studies have assessed the effects of large dams on fishes and macroinvertebrates, but few have examined the effects of lowhead dams. We sampled fishes, macroinvertebrates, habitat, and physicochemistry monthly from November 2000 to October 2001 at eight gravel bar sites centered around two lowhead dams on the Neosho River, Kansas. Sites included a reference site and a treatment site both upstream and downstream from each dam. Multivariate analysis of variance indicated that habitat, but not physicochemistry, varied immediately upstream and downstream from the dams, with resultant effects on macroinvertebrate and fish assemblages. Compared with reference sites, upstream treatment sites were deeper and had lower velocities and downstream treatment sites were shallower and had higher velocities; both upstream and downstream treatment sites had greater substrate compaction than reference sites. Macroinvertebrate richness did not differ among site types, but abundance was lowest at downstream tre...

Analysis of variance results showed significant differences in measurements on 71 specimens of Aphredoderus sayanus comparing standard length (F = 21.91, P < 0.0001), maximum depth (F = 8.44, P = 0.006), and standard length to body depth ratio (F = 9.11, P = 0.004), indicating that this fish is sexually dimorphic with females being larger and more full-bodied than males. In laboratory observations, a pair of A. sayanus created a nest and successfully spawned, which strengthens the argument that this fish might not be a branchial brooder but instead might be a nest builder with the female releasing adhesive eggs in the proximity of the nest. On three separate daytime occasions, A. sayanus ventured outside its refuge approximately to the point that only its head and anus were exposed, defecated, and then backed into its refuge. The jugular position of the anus might allow adult A. sayanus to partially leave its refuges to defecate to avoid altering water quality and without fully exposing itself to...

Freshwater mussels are declining rapidly in many parts of their range throughout North America, primarily as a result of anthropogenic alterations of their habitat, including damming of rivers. To assess the effects of lowhead dams on freshwater mussel assemblages in the Neosho River, Kansas, we sampled mussels by groping along transects and searching haphazardly along a 100-m stretch at eight sites of four site types (i.e., upstream reference, upstream treatment, downstream treatment, and downstream reference) centered around two lowhead dams. We collected from four to 11 species of mussels at each site, and a total of 13 species. Analysis of variance indicated a significant difference in mean species richness and evenness, but not abundance, among site types, consistent with the hypothesis that lowhead dams affect freshwater mussel assemblage composition in the Neosho River.

Translocation of freshwater mussels is a conservation tool used to reintroduce extirpated populations or augment small populations. Few studies have evaluated the effectiveness of translocations, mainly because estimating survival is challenging and time-consuming. We used a mark-recapture approach to estimate survival of nearly 4,000 individually marked Clubshell (Pleurobema clava) and Northern Riffleshell (Epioblasma rangiana) translocated to eight sites over a five-year period into the Salt Fork and Middle Fork Vermilion rivers in central Illinois. Survival differed among sites and between species; Clubshell were approximately five times more likely to survive than Northern Riffleshell. Survival also increased in the fourth year following a release and decreased following high-flow events. Translocating numerous individuals into multiple sites over a period of years could spread the risk of catastrophic high-flow events and maximize the likelihood for establishing self-sustaining populations.

Despite the increasing use of passive integrated transponder (PIT) tags in freshwater mussel research and conservation, there has been no evaluation of the trade-offs in cost and effort between commonly used adhesive types. These factors could be important to consider if tag retention rates do not vary by adhesive, the effects of handling are large, or resources are limited. We modeled and evaluated how material costs and effort function over a range of sample sizes by using field data from the relocation of 3,749 PIT-tagged Clubshell (Pleurobema clava) and Northern Riffleshell (Epioblasmarangiana) in Illinois, 261 Eastern Elliptio (Elliptio complanata) in Maryland, and the release of 99 Cumberland Combshell (Epioblasma brevidens) in Virginia. Each study used externally affixed 12.5-mm, 134.2-kHz PIT tags, but used a different adhesive to encapsulate tags (Illinois, underwater epoxy resin; Maryland, surface-insensitive gel cyanoacrylate; and Virginia, dental cement). We determined the total cost-per-tag-effort (CPTE) after parameterizing cost, quantity required, application time, and time for each adhesive. After accounting for standardized costs of staff time and adhesive, cyanoacrylate was the least costly adhesive to affix, encapsulate, and cure PIT tags on a per mussel basis. Differences in CPTE were small when the number of mussels tagged was low, but they increased by US$2–6 mussel-1. A primary goal in mussel projects is reduced stress from aerial exposure. Using underwater epoxy, which requires time above water to cure, can negate this goal and increase costs as it requires more handling effort than cyanoacrylate or dental cement. Nevertheless, more resourceintensive adhesives may still be an appropriate choice when the number of study animals is low. Further study is warranted to understand how our model may vary by adhesive brand, application rate, staffing level, and environmental factors.

Freshwater gastropods are one of the most imperiled groups of organisms in North America (Brown et al. 2008; Lysne et al. 2008). Of the seven gill-breathing operculate snails (Gastropoda: Prosobranchia) reported from Kansas, two are considered extirpated and the other five have shown substantial range reductions during the past century (Angelo et al. 2002). The primary causes for this decline include anthropogenic disturbances, sporadic shifts in climate, and evolving stream drainage patterns (Angelo et al. 2002; Brown et al. 2008).

Pimephales (Pisces: Cyprinidae) are among the most common eastern North American freshwater fishes (Page and Ceas 1989). The four species of Pimephales (bluntnose minnow P notatus, fathead minnow P promelas, slim minnow P tenellus, and bullhead minnow P vigilax) have evolved reproductively-associated morphological features (e.g. males develop secondary sexual characteristics) and complex breeding behaviors (e.g. egg-clustering breeding strategy) (McMillian and Smith 1974; Page and Ceas 1989; Tiemann 2007). Because of their use in the aquaculture industry, much has been published on P notatus and P promelas (e.g. Gale 1983; Clemment and Stone 2004), but little is known about the reproductive traits of P tenellus and P vigilax. The objective of this study was to determine fecundity (number of eggs) and egg size in P tenellus and P vigilax.

Freshwater mussels have undergone dramatic population declines due largely to habitat alteration. A commonly employed measure to minimize the effects of anthropogenic habitat disturbance on mussels is short-distance relocations of individuals. However, quantified survival data are lacking to gauge the success of relocations. To evaluate the suitability of short-distance relocations as a conservation tool for freshwater mussels, we experimentally relocated two common species, Mucket (Actinonaias ligamentina) and Plain Pocketbook (Lampsilis cardium), in an active construction zone. We marked 100 mussels with passive integrated transponders, released them ∼200 m upstream of the construction site, and monitored them monthly throughout the spring and summer 2013–2015. We used Cormack-Jolly-Seber models to estimate apparent survival rates and found survival was lowest the first two months after relocation but increased and stabilized thereafter. Our models predict 93% of the relocated A. ligamentina and 71% of the L. cardium remained alive three years post-relocation. We conclude short-distance relocations are a viable minimization tool for protecting freshwater mussels at bridge construction sites, but further study is needed examine the factors driving the initial mortality.