Publications by Year: 2013

Martin, Douglas F, Adam E Cohen, Ben J Labay, Melissa J Casarez, and Dean A Hendrickson. 2013. “Apparent Persistence of a Landlocked Population of Gulf Pipefish, Syngnathus scovelli.” The Southwestern Naturalist 58 (3): 376 - 378. Publisher's Version
Oldfield, Ronald G, Rayna M Harris, Dean A Hendrickson, and Hans A Hofmann. 2013. “Arginine Vasotocin and Androgen Pathways are Associated with Mating System Variation in North American Cichlid Fishes.” Hormones and Behavior. Publisher's VersionAbstract
AbstractNeuroendocrine 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.
Labay, Ben J, Adam E Cohen, Dean A Hendrickson, Blake Sissel, Sahotra Sarkar, and Melissa Casarez. 2013. Final Report: Data compilation, distribution models, conservation planning, and status survey for selected fishes of concern in Texas and region. Austin, Texas: University of Texas at Austin, 1 - 70. Publisher's VersionAbstract
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.
Cohen, Adam E, Ben J Labay, Dean A Hendrickson, Melissa Casarez, and Sahotra Sarkar. 2013. Final Report: Data provision and projected impact of climate change on fish biodiversity within the Desert LCC. Submitted to United States Department of the Interior, Bureau of Reclamation, Desert Landscape Conservation Cooperative; Agreement Number: R11A. Austin, Texas: University of Texas at Austin, 1 - 109. Publisher's VersionAbstract
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.
Hendrickson, Dean A, and Adam E Cohen. 2013. “Fishes of Texas Project and Online Database (” Fishes of Texas Project and Online Database ( Publisher's VersionAbstract
The Fishes of Texas Project ( 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.
Martin, Douglas F, Adam E Cohen, Benjamin J Labay, Melissa Casarez, and Dean A Hendrickson. 2013. “Persistence of a landlocked population of Gulf pipefish, Syngnathus scovelli..” The Southwestern Naturalist 58 (3): 378 - 380.Abstract
Though adults and older juveniles of some species are commonly encountered in freshwaterreaches of coastal streams and rivers, pipefishes in general are believed to be either amphidromous or marine. In 1992, Gulf pipefish (Syngnathus scovelli) were reported in Lake Texana, a reservoir on the Navidad River near Edna, Jackson County, Texas. In June 2011, we collected an adult male with embryos and a juvenile from the same lake. This strongly suggests reproduction and persistence of the population at Lake Texana, which does not have access to saline waters. Though presence of a viable, reproducing population was not absolutely confirmed this appears likely to be the first known landlocked, freshwater population of any species of pipefish. RESUMEN—Aunque adultos y juveniles mayores de algunas especies se encuentran com´unmente en aguas dulces de arroyos y r´ıos costeros, en general se considera que las especies de pez pipa son anf´ıdromas o marinas. En 1992, el pez pipa del Golfo (Syngnathus scovelli) fue reportado en el Lake Texana, una presa artificial sobre el r´ıo Navidad cerca al poblado de Edna, condado de Jackson, Texas. En junio de 2011, colectamos un macho adulto con embriones y un juvenil en el mismo lago, hecho que sugiere la reproducci´on y persistencia de la poblaci ´on del Lake Texana, el cual no tiene acceso a aguas salobres. Aunque no se ha confirmado absolutamente, parece muy probable que esta poblaci ´on represente la primera poblaci ´on de pez pipa que puede reproducirse en agua dulce sin tener salida a agua salobre.