Rivers and streams of the southern United States contain more than 1,800 aquatic species, 500 of which are regionally endemic. At present, 34% of the fish species and 90% of the mussel species in peril nationwide are found in these systems. Declines in these imperiled species are due to many factors, including hydrologic alteration, degraded water quality, loss of instream and watershed connectivity, physical habitat degradation, and the negative effects of nonindigenous species (e.g., predation on, competition with, and hybridization with native forms). In addition, this situation is exacerbated through human population growth, competing water demands, land-use changes, and other interrelated issues. If unchecked, these issues will likely continue to contribute to the imperilment and loss of native species in the region. Of the nine described species and subspecies of black bass, six are endemic to the southern United States: Guadalupe Bass Micropterus treculii, Shoal Bass M cataractae, Redeye Bass M. coosae, Florida Bass M floridanus, Alabama Bass M henshalli, and Suwannee Bass M notius. In addition, undescribed species and subspecies also exist and all are in need of conservation measures to prevent them from becoming imperiled. In an effort to focus and coordinate actions to support the long-term persistence of endemic black bass populations, local, state, and federal agencies, universities, nongovernmental organizations, and corporations from across the region joined with the National Fish and Wildlife Foundation to form the Native Black Bass Initiative (NBBI). The NBBI provides regional conservation strategies, objectives, and targets to restore and preserve functional processes in those watersheds that support natural habitat conditions and sustainable populations of endemic black bass and other native fishes of the region. Initial actions implemented through the NBBI focus on addressing the conservation needs of Guadalupe Bass in streams of the Edwards Plateau ecoregion of Texas, Redeye Bass in the Savannah River watershed of Georgia and South Carolina, and Shoal Bass populations in the Apalachicola River watershed of Alabama, Florida, and Georgia.

Recent literature reviews of bioassessment methods raise questions about use of least-impacted reference sites to characterize natural conditions that no longer exist within contemporary landscapes. We explore an alternate approach for bioassessment that uses species site occupancy data from museum archives as input for species distribution models (SDMs) stacked to predict species assemblages of freshwater fishes in Texas. When data for estimating reference conditions are lacking, deviation between richness of contemporary versus modeled species assemblages could provide a means to infer relative biological integrity at appropriate spatial scales. We constructed SDMs for 100 freshwater fish species to compare predicted species assemblages to data on contemporary assemblages acquired by 4 independent surveys that sampled 269 sites. We then compared site-specific observed/predicted ratios of the number of species at sites to scores from a multimetric index of biotic integrity (IBI). Predicted numbers of species were moderately to strongly correlate with the numbers observed by the four surveys. We found significant, though weak, relationships between observed/predicted ratios and IBI scores. SDM-based assessments identified patterns of local assemblage change that were congruent with IBI inferences, however, modeling artifacts that likely contributed to over-prediction of species presence may restrict the stand-alone use of SDM-derived patterns for bioassessment and therefore warrant examination. Our results suggest that when extensive standardized survey data that includes reference sites are lacking, as is commonly the case, SDMs derived from generally much more readily available species site occupancy data could be used to provide a complementary tool for bioassessment.

Sharpnose shiner, Notropis oxyrhynchus, was recently listed as federally endangered  Known from the Brazos and Colorado Rivers, but Colorado population believed to be introduced and now extinct  Our species distribution models indicate sufficient habitat for the species to occur in the Colorado (Fig. 3).  Our previous work (Fig. 1) to verify cyprinid museum specimens in the Colorado indicate 5 records of N. oxyrhynchus collected from 1884 to 1955 strongly suggesting nativity of the species (or a morphologically similar form) Visual examination of specimens from the Colorado suggest distinctive morphological (shape) differences compared to Brazos specimens  We hypothesized Colorado population might be a separate or incipient species

Behavioral studies have often examined parental care by measuring phenotypic plasticity of behavior within a species. Phylogenetic studies have compared parental care among species, but only at broad categories (e.g., care vs. no care). Here we provide a detailed account that integrates phylogenetic analysis with quantitative behavioral data to better understand parental care behavior in the Cuatro Ciénegas cichlid, Herichthys minckleyi. We found that H. minckleyi occurs in a clade of sexually monochromatic or weakly dichromatic monogamous species, but that male and female H. minckleyi have dramatically different reproductive coloration patterns, likely as a result of sexual selection. Furthermore, we found that males are polygynous; large males guard large territories, and smaller males may attempt alternative mating tactics (sneaking). Finally, compared to the closely related monogamous Rio Grande cichlid, H. cyanoguttatus, males of H. minckleyi were present at their nests less often and performed lower rates of aggressive offspring defense, and females compensated for the absence of their mates by performing higher levels of offspring defense. Body color, mating system, and parental care in H. minckleyi appear to have evolved after it colonized Cuatro Ciénegas, and are likely a result of evolution in an isolated, stable environment.

Background/Question/Methods Invasive species are commonly cited as one of the top threats to global biodiversity. The IUCN Red List database indicated that invasives are contributing threats 292 extinct, extinct in the wild, critically endangered or endangered fishes. The aquarium trade is one of five main pathways by which aquatic species are introduced to a new location. Hemichromis guttatus, a popular ornamental cichlid native to West Africa, is one of these species having been introduced into an endemic hotspot in northern Mexico, the desert spring system Cuatro Cienegas, where it has established, is spreading and is in the process of becoming invasive. This site provides the opportunity to study an invasion in progress and to make predictions about to where H. guttatus may spread, and then to test these predictions. In this work, we asked what is the invasion risk of currently uninhabited sites within Cuatro Cienegas? To do this, we conducted a valley-wide survey of H. guttatus and collected data on the environmental characteristics at each trap site. We then used logistic regression to model which environmental characteristics were related to presence of the exotic and used these results to assign invasion risk to as-of-yet uninhabited sites throughout the valley. Results/Conclusions We found that the model that best predicted Hemichromis guttatus presence included pH, temperature2 (indicating a non-linear relationship between temperature and presence), depth and vegetation presence. However, only pH, temperature2 and vegetation presence were significant predictors, indicating a threshold level of depth below which presence is much more probable, yet under which, there is no clear pattern between depth and the probability of presence. Using these results, we were able to identify sites with a very high, high, moderate and low invasion risk in the valley. Generally, invasion risk declined as sites were further away from thermal spring inputs i.e., downstream in the large river system, and higher closer to these sites. Some sites with a high risk of invasion have surface connections to known presences of H. guttatus while others with a high invasion risk are more isolated, thus dispersal limitation could interact with the environmental characteristics of a site to slow unaided invasion into these more isolated sites. These results will be beneficial to reserve managers in terms of deciding how to prioritize where to use the limited resources available to them to combat the spread of H. guttatus in the valley.

Abstract The variable platyfish (Xiphophorus variatus), native to Gulf Coast drainages of northern Mexico, is a popular aquarium fish with a long history of introduction globally. We document the first Texas occurrence of this species, and its persistence in highly urban Waller Creek in the city of Austin since at least 2004. The population appears to be limited to Waller Creek, having not yet been found in neighboring creeks where similar habitat exists. We observed individuals in situ and in the lab surviving in 7°C water, well below published thermal minima, and report its persistence through one of the coldest winters in Austin's recorded history. Its persistence may be due to a combination of its cold tolerance and the presence of thermal refuges. In the lab we found that individuals purchased in a local pet store and individuals from Waller Creek had the same cold tolerance. , Resumen El pez espada de Valles (Xiphophorus variatus), nativo de las cuencas afluentes del golfo de México del norte de México, es una especie popular de acuario con una historia larga de introducciones globales. Aquí documentamos la primera ocurrencia de la especie en Texas y su persistencia en un arroyo urbano, Waller Creek en la ciudad de Austin, a partir de por lo menos 2004. La población parece limitada a Waller Creek porque aún no se ha encontrado en arroyos cercanos con hábitat similar. Observamos individuos in situ y en el laboratorio sobreviviendo en agua de 7°C, mucho más frio que la mínima tolerancia termal publicada, y reportamos su persistencia a través de uno de los inviernos más fríos en la historia de Austin. Su persistencia puede ser atribuida a una combinación de su tolerancia al frío y existencia de refugios termales. En el laboratorio, individuos comprados en una tienda local de acuario e individuos de Waller Creek mostraron la misma tolerancia al frío.

Since Barbour proposed sympatric speciation to explain evolution of silversides in the Lerma-Santiago basin, relatively little subsequent study has been done. We assessed foraging patterns of four sympatric silversides species (Chirostoma estor, Chirostoma grandocule, Chirostoma attenuatum and Chirostoma patzcuaro) in Lago de Pátzcuaro to understand resource partitioning and their sympatric coexistence. We assessed the abundance of invertebrate prey in three feeding habitats and measured physical and chemical habitat parameters at two study sites. Fish were collected during the wet (September 1987) and dry (March 1988) seasons; a total of 242 gut contents were analyzed. We evaluated the trophic guild of each species using the index of relative importance (IRI), prey selectivity with the Ivlev Electivity Index (E), dietary diversity using Shannon and Wiener diversity index (H’), and diet overlap using Morisita index. All silverside species were determined to be predaceous carnivores that feed mainly on nekton and periphyton. Dietary diversity and prey selectivity patterns were similar among species and diet overlap was \textgreater70%. Our data do not support the proposition that coexistence of these four fish species is maintained by dietary specialization. We hypothesize that sympatric coexistence of atherinopsids in Lago de Pátzcuaro is explained by food resource availability and ontogenetic variation in their diets. This study highlights the importance of analyzing ecological patterns and mechanisms as basic elements for designing conservation strategies of species flocks, especially under habitat loss and introduction of exotic species. Conservation efforts are urgent to preserve the rare evolutionary process of sympatric speciation (habitat segregation) that is occurring in other lakes in central Mexico, and probably already lost in the Lago de Pátzcuaro, as a result of poor management and inadequate conservation strategies.

Numerous published reports indicate that records of occurrence of Sharpnose Shiner, Notropis oxyrhynchus, in the Colorado River basin of Texas are the result of an introduction, though the species is clearly native in the adjacent Brazos River basin. We discovered previously mis-identified specimens of N. oxyrhynchus that extend the record of presence of the species in the Colorado basin much further back in time than previous authors realized, and conclude that the species was almost certainly native there. However, lack of the species in any of the many collections made in the basin over the last half century indicates a low probability that it still persists there.

Strategic conservation planning for broad, multi-species landscapes benefits from a data-driven approach that emphasizes persistence of all priority species populations and utilized landscapes, while simultaneously accounting for human uses. This study presents such an assessment for priority fishes of the Great Plains of the United States. Species distribution models for 28 priority fishes were created and incorporated into a prioritization framework using the open source software Zonation, accounting for species-specific connectivity needs and current fish habitat condition. Multiple additional assessments were then produced that i.) identify distinct species management units based on distance and compositional similarity of stream segments containing priority species, ii.) compare results of ranking species' conservation values at the local (state) and global scale, and iii.) provide 'bang-for-buck' perspectives, emphasizing richness of priority species, at state and major basin scales. Together, these analyses are intended to aid managers in effective allocation of conservation action with regards to imperiled fishes of the Great Plains. Implementation of a broad-scale multi-species approach such as this complements traditional reactive management and restoration by encouraging cooperation and coordination among stakeholders and partners, increasing efficiency of future monitoring and management efforts.

The Fishes of Texas Project (www.fishesoftexas.org) compiled Texas fish species occurrence records from 42 museum collections and applied rigorous quality control and data normalization / standardization to result in 124,415 specimen-based records collected between 1851 and 2010 by 5,924 collectors. 88,348 records from 7,868 unique Texas inland localities were manually georeferenced with placement error estimates. 8,460 Gulf of Mexico records and 18,923 inland records from neighboring Mexican and U.S. states have been partially processed. Georeferenced records were plotted and 4,107 geographic outliers flagged as potential identification or location errors. Most flagged specimens, and often related original documentation, have now been examined and identifications corrected or confirmed. The value of such specimen-based vouchering of collections and compiling and normalizing large data sets was quickly demonstrated by discovery of 35 species occurrences in major river basins where they were previously not believed to occur. The online database can be queried in diverse ways, mapped, and records downloaded. Also online are a large set of high quality fish images, original field notes, specimen photos, detailed species distribution models based on the data, accounts of species' biology and ecology, video time-lapse distribution maps, and digital identification keys.

The four primary objectives of this project were to: (1) compile a dataset of georeferenced range-wide occurrence records for 6 target fish species (Notropis buccula, N. oxyrhynchus, N. girardi, Hybognathus amarus, Platygobio gracilis, Macrhybopsis tetranema, Pteronotropis hubbsi, and Percina maculata); (2) use a high quality and geographically wide-ranging subset of those data to create species distribution models (SDM’s), which convert point occurrences into a continuous probability coverage; (3) use those models in conjunction with 130 additional SDM’s (previously created) to develop modeled conservation priority areas for Texas; and (4) complete a status survey for N. oxyrhynchus and N. buccula in the mainstem of the middle Brazos River. The dataset provided, derived from 51 original sources, includes 11,082 records, of which we were able to georeference 3,675 (33%). This number of records was sufficient for constructing SDM’s for the six target species, with all models meeting quality assurance criteria. Using these models, conservation area prioritizations were developed for Texas under several guiding criteria for decision making. The field survey sampled the mainstem Brazos at 20 sites between Possum Kingdom Reservoir and Bryan, TX, collecting 65,840 fish specimens representing 46 species. Neither survey target species was collected, suggesting absence or extreme rarity of both in this reach of the Brazos at the time of sampling. Collection sites upstream of Waco, compared to those downstream of that city, were less diverse in cyprinids and more diverse in non-native species, suggesting more heavily impacted habitat upstream of Waco. All raw data used in analyses and results of analyses and the field survey are provided with the written report.

The four primary objectives of this project were to: (1) compile a dataset of fish occurrence records for the entirety of the Rio Grande drainage in the US and Mexico; (2) improve that dataset by reformatting dates, synonymizing species names to a modern taxonomy, georeferencing localities, and flagging geographic outliers; (3) for those species with enough data sufficient for modeling, create species distribution models (SDM’s); (4), use the environmental conditions determined via those models to project the species distributions into the future under two climate scenarios. We compiled 495,101 fish occurrence records mined from 84 original sources into a single database. We then, on the basis of text string searches of the original sources’ verbatim locality fields, indicating a reasonable likelihood of being from the Rio Grande drainage, extracted 145,426 records for which we edited taxonomy, reformatted dates, and finally georeferenced 59,156 (41%) records that proved sufficient for constructing SDM’s for 36 species that met a priori quality assurance criteria. We provide basic interpretation of these models and discuss projections of them into several different future climate forecasts. Products include raw model outputs and symbolized maps helpful in interpretation and comparison, as well as raw data sets and recommendations regarding how all of these product might be used in future management efforts.

Abstract Neuroendocrine pathways that regulate social behavior are remarkably conserved across divergent taxa. The neuropeptides arginine vasotocin/vasopressin (AVT/AVP) and their receptor V1a mediate aggression, space use, and mating behavior in male vertebrates. The hormone prolactin (PRL) also regulates social behavior across species, most notably paternal behavior. Both hormone systems may be involved in the evolution of monogamous mating systems. We compared AVT, AVT receptor V1a2, PRL, and PRL receptor PRLR1 gene expression in the brains as well as circulating androgen concentrations of free-living reproductively active males of two closely related North American cichlid species, the monogamous Herichthys cyanoguttatus and the polygynous H. minckleyi. We found that H. cyanoguttatus males bond with a single female and together they cooperatively defend a small territory in which they reproduce. In H. minckleyi, a small number of large males defend large territories in which they mate with several females. Levels of V1a2 mRNA were higher in the hypothalamus of H. minckleyi, and PRLR1 expression was higher in the hypothalamus and telencephalon of H. minckleyi. 11-ketotestosterone levels were higher in H. minckleyi, while testosterone levels were higher in H. cyanoguttatus. Our results indicate that a highly active AVT/V1a2 circuit(s) in the brain is associated with space use and social dominance and that pair bonding is mediated either by a different, less active AVT/V1a2 circuit or by another neuroendocrine system.

The Fishes of Texas Project (www.fishesoftexas.org) compiled Texas fish species occurrence records from 42 museum collections and applied rigorous quality control and data normalization/standardization to result in 124,415 specimen-based records collected between 1851 and 2010 by 5,924 collectors. 88,348 records from 7,868 unique Texas inland localities were manually georeferenced with placement error estimates. 8,460 Gulf of Mexico records and 18,923 inland records from neighboring Mexican and U.S. states have been partially processed. Georeferenced records were plotted and 4,107 geographic outliers flagged as potential identification or location errors. Most flagged specimens, and often related original documentation, have now been examined and identifications corrected or confirmed. The value of such specimen-based vouchering of collections and compiling and normalizing large data sets was quickly demonstrated by discovery of 31 species occurrences in major river basins where they were previously not believed to occur. The online database can be queried in diverse ways, mapped, and records downloaded. Also online are a large set of high quality fish images, original field notes, specimen photos, detailed species distribution models based on the data, accounts of species' biology and ecology, video time-lapse distribution maps, and digital identification keys.

Development of species distribution models (SDMs) and application of them has been expanding very rapidly over the past few years. Often based on simple occurrence data like that provided by the Fishes of Texas project, they summarize and make these data sets useful in new ways and across large spatial extents. They have proven useful in diverse applications such as conservation planning, climate change studies, disease ecology, invasive species research, and community ecology. As a first step toward many future landscape-scale geospatial analyses using Fishes of Texas data, we developed powerful predictive computer models of species’ distributions using commonly accepted practices and modeling algorithms and provide them here so that others may use them in their own research and applications. Our models provide continuous coverages of probabilities of species occurrences across all cells of a fine-scale grid extending across all of Texas, thus effectively “filling in the blanks” between the actual occurrences that we know to be distributed in non-random ways as a result of diverse historic factors such as collectors' interests, gears, landowner permission, etc. We developed these models using only the most precisely located recent occurrence records in the Fishes of Texas database together with recent climate and physical environmental data. These models have now been thoroughly tested and demonstrated to be powerful predictors of actual occurrences under current conditions. They were constructed in such a way that the probability values in the models can be interpreted as indicators of suitability of habitat that are mostly independent of large scale land and water development influences such as diversions or dams. Mapped modeled probabilities of species occurrences can be viewed and model outputs formatted for analysis may be downloaded via the model class table below. At this time only Model Class 01 are available for download. When using models, please cite as suggested in the How to cite models section of the Fishes of Texas documentation.

Terrapene coahuila is one of four extant species of North American box turtles. It is restricted in distribution to the Cuatro Ciénegas Basin in Coahuila, México. Results of previous examinations of extant T. carolina and T. ornata revealed relatively high levels of morphological variation, but morphological studies of T. coahuila are rare, and data on skeletal morphology are limited. We examined 214 skeletal specimens of T. coahuila and documented variation in 51 mensurative and discrete characters of the carapace and plastron. Overall levels of variation are low, as predicted by previously documented levels of gene flow between the sub-populations of the species. However, significant polymorphism is present in the positions of the anterior and posterior sulci of the fourth vertebral scute and the configuration of neural bones 2, 3, and 7. Additionally, co-ossification of the carapacial bones varies substantially within the sample, but independently of carapace length. Genetic, epigenetic, and environmental controls for those features are not known. In addition to documenting skeletal morphology within T. coahuila, we provide new perspectives on patterns of variation within Terrapene, and contribute data that should help paleontologists to establish more rigorous criteria for the identification of fossil specimens of North American box turtles. Those data will be especially important for critical evaluation of recently discovered early and middle Tertiary fossils that are yielding new insights into the evolution of box turtles and the modernization of the turtle biota.