161 research outputs found
Recommended from our members
Interim progress report on a study of the utility of data obtainable from otoliths to management of Humpback Chub (Gila cypha) in the Grand Canyon
Daily growth increments of otoliths of fishes have been useful in many fishery applications since they have been demonstrated to provide a precise method of ageing individuals and reconstructing individual growth and, possibly, movement or habitat histories. These techniques have not been previously applied to humpback chub, but are believed to have considerable potential for providing knowledge of this difficult to sample and little-understood species. Large temperature and water quality gradients apparently traversed by individuals of this species in the Grand Canyon are of a magnitude likely to produce structural and/or chemical signals in the crystalline calcareous otoliths. If so, since otoliths grow by accretion of daily increments (much like trees develop yearly growth rings), and are stable structures, which unlike scales, are not susceptible to reabsorption except in the most extreme conditions, they retain a structural and chemical chronology of habitats occupied. If the relationships of ambient physical and chemical conditions to otolith structure and composition can be described, a chronology of habitat occupancy and growth for individuals could theoretically be reconstructed with daily precision. Such reconstructions of growth rates, birth dates, movement histories, and possibly, birth place (based on chemistry at otolith formation or during early life), could provide extremely valuable life-history information regarding timing of spawning, cohort recruitment, mortality rates, and data on other population parameters critical for management of this endangered species.
The feasibility of using otoliths and opercles of humpback chub for age estimation of individuals has been preliminarily investigated by examining otoliths and opercles from a total of 47 juvenile (ages 0 through 1 +)and 43 adult (estimated ages 2- 23) specimens collected in the Little Colorado River (71 specimens) and mainstream Colorado River (19 specimens) at various places in the Grand Canyon between 1988 and 1992. Studies are continuing, and at this point, due to both sample size and numerous other limitations, and ongoing refinements of techniques, conclusions made here are highly preliminary.
Structures prepared and examined included opercles of 35 specimens, one asteriscus from each of 47 specimens and a lapillus from each of 56 specimens. Seventeen specimens were evaluated using all three calcareous structures (lapillus, asteriscus and opercle). The sagitta was also examined, but found to be unsuitable for ageing purposes due to its long, delicate form and irregular increments after the larval/juvenile stage. Additional lapilli have been removed from other available specimens, and a complete inventory of specimens available for further study of calcified structures is provided.
Studies of micro-spatial variation in chemical composition of selected lapilli is in progress, using the highly accurate proton probe at the Institute of Geological and Nuclear Sciences in Lower Hutt, New Zealand. This method of analysis shows great promise of overcoming what has been indicated in recent literature to be significant inaccuracies of other techniques (Energy Dispersive X-ray diffraction and Wave Length dispersive X-ray diffraction) used in many of the published studies of microspatial elemental analysis of otoliths.Arizona Game and Fish DepartmentIntegrative Biolog
Recommended from our members
Fishes of Texas Project: Data Visualization and Analysis Tools
Poster presentation presented at the 2020 Texas Chapter of the American Fisheries Society annual meeting in Waco, Texas on January 24, 2020.The Fishes of Texas Project (FoTX) (http://fishesoftexas.org) database currently has 124,452 specimen-vouchered occurrence records spanning > 150 years with over 400,000 new records (including non-vouchered sources such as literature, anecdotal, and photo-based) in the process of being imported. Continual data growth prompted creation of new tools to dynamically assess (as the data evolve) the state of data coverage across various dimensions to increase user understanding and accessibility to the data and improve overall utility of the project. We produced species sampling curves, temporal species accumulation graphs, and heat maps of collecting event density over time and space for each river sub-basin within Texas. A QGIS plugin was also created to better assess the suspect status of incoming records. Each type of visualization has basic documentation, easily accessible statistical summaries, flexible queries, and exploration tools to help reveal variations in sampling density over both temporal and spatial dimensions. We highlight here the San Bernard River as an example of a notably under-sampled sub-basin (as indicated by diverse forms of evidence). With addition of future records, these dynamic tools will continue to illustrate taxonomic and spatial sampling deficiencies that in turn will help guide conservation planning.Texas Parks and Wildlife Department, under the U.S. Fish and Wildlife Service State Wildlife Grant Program, grant TX T-180-R-1, F17AF01129 (CFDA# 15.634)Integrative Biolog
Recommended from our members
Documentation Related to a 1991 Observation of Sturgeon in the Rio Grande – Río Bravo, USA (Texas) and Mexico (Coahuila)
This digital archive provides a compilation of previously unpublished information regarding a 1991 observation of a live sturgeon (Family Acipenseridae) in the Rio Grande-Río Bravo of the USA and Mexico. Though a few specimens collected in the 19th century support occurrence of sturgeon in this river basin, lack of credible, recent records has often led to this species not being recognized as part of the basin’s native fish fauna, and certainly not part of its modern fish community.
The second and third authors of this document manage the Fishes of Texas Project (Hendrickson, Dean A., & Cohen, Adam E. (2015). Fishes of Texas Project Database (version 2.0). Texas Advanced Computing Center, University of Texas at Austin. http://doi.org/10.17603/C3WC70) and knew of the unpublished 1991 observation of sturgeon reported here. They requested the content provided here from first author (Platania) who provided what follows below (verbatim as received in April 2018) and permission to archive it for public access.Integrative Biolog
The Mexican Blindcat Project: new discoveries and future efforts
content from an oral presentation March, 2017 at the 5th Astyanax International Meeting (http://www.stowers.org/sites/all/themes/aimfc/aim2017_prog.pdf)The endangered Mexican blindcat (Prietella phreatophila, Carranza 1954) is one of only four
stygobitic ictalurid catfish in North America. Members of two monotypic genera (Satan
eurystomus and Trogloglanis pattersoni) are known from the Edwards Aquifer in Texas and, until
recently, Prietella (represented by P. lundbergi and P. phreatophila) was only known to occur in
Mexico (northern Coahuila to southern Tamaulipas). The recent discovery of P. phreatophila in
a cave on the Amistad National Recreation Area in Val Verde County, Texas is the result of
decades of sporadic effort on both sides of the US/Mexican border and has stimulated a renewed
effort to investigate the distribution, ecology, evolutionary history, and conservation status of this
species. Collaborative efforts among The San Antonio Zoo, The University of Texas at Austin,
Zara Environmental and The National Park Service are currently focused on habitat surveys in
Texas as well as captive husbandry and propagation. Future efforts will include collaborators from
the Comisión Nacional de Áreas Naturales Protegidas, Área de Protección de Recursos Naturales
Sabinas, and the Laboratorio de Genética para la Conservación, Centro de Investigaciones
Biológicas del Noroeste, La Paz to conduct expanded fieldwork in Mexico, hydrogeologic studies,
and surveys using environmental DNA.San Antonio Zoo; University of Texas at Austin, Biodiversity Center, College of Natural Sciences; U.S. National Park ServiceIntegrative Biolog
Recommended from our members
Year 1 report for ‘Conserving Texas Biodiversity: Status, Trends, and Conservation Planning for Fishes of Greatest Conservation Need’
State Wildlife Grant Program, grant TX T-106-1 (CFDA# 15.634), Contract No. 459125 UTA14-001402Substantive progress was made on all major Project Activities in this first year:
Activity 1. Coordinate and Facilitate Science and Conservation Actions for Conserving Texas Biodiversity - We expanded and strengthened UT-TPWD coordination, transitioning the relationship between these partners into a much more collaborative one than was previously realized. The flow of data between TPWD and the Fishes of Texas Project (supported in part by this project) has become much more bi-directional. Many newly collected TPWD specimens, agency databases, legacy data products and reports, and feedback from resource managers are now beginning to contribute substantively to growth and diversity (now including non-specimen-vouchered records) of data served through the FoTX Project’s websites. Work on cleaning and normalizing of FoTX’s online specimen-vouchered database continued, and the updated FoTX occurrence and distribution data are being actively used. Most recently they were used by this project, together with expert (TPWD, UT and others’) opinions, to develop recommendations on conservation status of native fishes of Texas’ Species of Greatest Conservation Need for TPWD’s consideration in anticipated updates to the Texas Conservation Action Plan. Within two months of this report, a new and substantially larger and improved version of the FoTX website/database and related collection of images, field notes, and ancillary datasets, will be formally announced.
Activity 2. Identify Priority Geographic Management Units for Conserving Fishes of Greatest Conservation Need - We used FoTX data in a systematic conservation area prioritization analysis to identify Native Fish Conservation Areas (NFCAs) for large portions of Texas where such comprehensive planning had not been previously carried out. Updated and new FoTX data for all Texas fish Species of Greatest Conservation Need (SGCN) were used in production of newly improved Species Distribution Models for input into this planning process, and the results of the planning exercise have already been integrated by TPWD into management prioritizations of both those species and the resultant NFCAs.
Activity 3. Develop Monitoring and Conservation Plans for Native Fish Conservation Areas - Monitoring and conservation plans were delivered to TPWD for all NFCAs identified in Activity 2.
Activity 4. Conduct Field-Based Surveys Detailed Biodiversity Assessments (i.e. Bioblitzing), and Citizen-Based Monitoring - Field surveys with detailed biodiversity assessments (“bioblitzes”) and citizen-based monitoring were conducted in three areas selected collaboratively by TPWD and FoTX Project staff from within the identified NFCAs: Nueces River headwaters, Big Cypress Bayou basin, and Village Creek basin. Along with this field effort, FoTX Project staff developed and circulated guidelines and best practices, and provided training for citizen-based monitoring that leverages iNaturalist for capture and reporting of photo-vouchered occurrence records in ways that will help assure scientifically useful data are obtained. All specimens acquired during these field efforts, and from many other routine specimen acquisitions from across the state (1845 total records/jars of specimens), were cataloged in the UT Fish Collection database. From there, these new records will soon be fed into GBIF, VertNet, FishNet2 and other major online data aggregators, including the online Fishes of Texas database.Texas Parks and Wildlife Department; U.S. Fish and Wildlife ServiceIntegrative Biolog
Recommended from our members
Verification of Identifications of Cyprinid Specimens from the Colorado River Basin, Texas
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.U.S. Fish & Wildlife Service, Arlington, Texas. FWS FBMS Agreement #: F12AP00622;
CFDA Number/Title: 15.650; non-Profit, AcademicTexas Natural Science Cente
Using the Fishes of Texas Project Databases and Recent Collections to Detect Range Expansions by Four Fish Species on the Lower Coastal Plain of Texas
The Fishes of Texas project online database is a large, freely available quality controlled fish occurrence database of museum vouchered specimens. We used data from it, the same project’s separate database of occurrences extracted from published literature and our own recent survey data to examine range stability for four fish species inhabiting the Texas Lower Coastal Plain: Fundulus chrysotus, Fundulus jenkinsi, Heterandria formosa and Poecilia formosa. A weakness of our data is that they consist of presences only and species absences can only rarely be inferred. To help adjust for this we used common widespread species as proxies for the four target species by using captures of these proxy species as indicators that the collecting methods used were appropriate to capture the target species, assuming then that large numbers of occurrences of the proxies with contemporaneous absence of the target species in the same samples supports inferences of probable absence of target species. We here report new and previously unpublished occurrences for these species and document westward range expansions for H. formosa and F. chrysotus, an eastward range expansion for P. formosa, and a pattern of possible range contraction and expansion for F. jenkinsi
Recommended from our members
Update on the Fishes of Texas Project
Poster presentation presented at the 2017 Texas Academy of Sciences annual meeting in Belton, Texas on March 4, 2017.The Fishes of Texas project (www.fishesoftexas.org), originating in 2006, remains the most reliable (quality
controlled) and data rich site for acquiring occurrence data for Texas fishes, holding over 124,000 records from
42 institutions. Among many discoveries, the project is responsible for detecting at least 3 freshwater species
not previously known from the state. We continue making improvements, but substantial updates so far have
been onerous for our developers for various reasons. A recent major update reduces coding redundancies,
points the website to a new massively restructured and more fully normalized PostgreSQL database (was
MySQL), and places the code in a versioning environment. These changes have little immediate effect on user
experience, but will greatly accelerate development. PostgreSQL allows for complex spatial queries which will
allow users to quickly map occurrence data alongside many more political/environmental layers than currently
possible. While our database/web designers have been implementing these changes and fixing bugs etc.,
we’ve been preparing resources for them to integrate into the website. Some highlights to expect: 1 new
updates to the state Species of Greatest Concern list; 2 expert opinion-determined nativity spatial layers for
all freshwater fishes displaying in our new mapping system; 3 dynamic statistical summaries; 4 new data types
from the literature (>14,900 records), citizen science (>4,300), anglers (>37,000), and agency databases
(>1,000,000); 5 new museum records, many derived from our gap sampling (~19,000, 4 museums); 6 more
specimen examinations (>400) and photographs (1000); 7 document archive with “smart” text search tools
(currently in beta testing using TPWD fisheries reports). So be patient and keep your eyes open for updates.University of Texas at Austin, Texas Parks and Wildlife Department, Texas Commission on Environmental Quality, U.S. Department of the Interior,Integrative Biolog
Recommended from our members
Preliminary Results of American Eel Sampling Efforts in Gulf of Mexico Drainages of Texas
American Eel Anguilla rostrata has a unique and complex life history that is fairly well-studied on the eastern coast of the United States, but few studies have been done on Gulf of Mexico drainages. To inform conservation and management decisions, efforts to better understand the population structure, seasonal dynamics, and life history of American Eel are underway. The primary objectives of our efforts are to assess the current and historical distribution and abundance, habitat use, movement patterns, parasite occurrence, diet and population structure of American Eel across all life stages in Gulf of Mexico drainages of Texas.Texas State Wildlife Grant Program grants T-173-R-1 and T-172-R-1 in cooperation with the U.S. Fish and Wildlife Service, Wildlife and Sport Fish Restoration ProgramIntegrative Biolog
Trophic polymorphism and behavioral differences decrease intraspecific competition in a cichlid, Herichthys minckleyi
Resource polymorphisms, or morphological variations related to resource use, are common in fishes and are thought to be a possible step in speciation. This study experimentally tests the hypothesis that fitness (as estimated by growth rates) is increased by the presence of multiple trophic morphotypes (or morphs) within a population. Cage experiments were used to quantify the intraspecific competitive interactions between morphs of the polymorphic cichlid Herichthys minckleyi in Cuatro Cienegas, Mexico. Results suggest that competition is reduced between morphs in mixed-morph treatments relative to equal-density single-morph treatments. Field studies revealed that the morphs feed in different microhabitats and use different feeding behaviors within these microhabitats. These results suggest that the polymorphism is maintained in the population because it decreases competition between the morphs, and that differences in feeding behavior facilitate resource partitioning
- …