Gopherus

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 2055 Experts worldwide ranked by ideXlab platform

Taylor Edwards - One of the best experts on this subject based on the ideXlab platform.

Kristin H Berry - One of the best experts on this subject based on the ideXlab platform.

  • enhancing and restoring habitat for the desert tortoise
    Journal of Fish and Wildlife Management, 2016
    Co-Authors: Scott R. Abella, Kristin H Berry
    Abstract:

    Abstract Habitat has changed unfavorably during the past 150 y for the desert tortoise Gopherus agassizii, a federally threatened species with declining populations in the Mojave Desert and western...

  • testing taxon tenacity of tortoises evidence for a geographical selection gradient at a secondary contact zone
    Ecology and Evolution, 2015
    Co-Authors: Taylor Edwards, Cristina A Jones, Richard D Inman, Kristin H Berry, Kenneth E Nussear, Todd C. Esque, Melanie Culver
    Abstract:

    We examined a secondary contact zone between two species of desert tortoise, Gopherus agassizii and G. morafkai. The taxa were isolated from a common ancestor during the formation of the Colorado River (4–8 mya) and are a classic example of allopatric speciation. However, an anomalous population of G. agassizii comes into secondary contact with G. morafkai east of the Colorado River in the Black Mountains of Arizona and provides an opportunity to examine reinforcement of species' boundaries under natural conditions. We sampled 234 tortoises representing G. agassizii in California (n - 103), G. morafkai in Arizona (n - 78), and 53 individuals of undetermined assignment in the contact zone including and surrounding the Black Mountains. We genotyped individuals for 25 STR loci and determined maternal lineage using mtDNA sequence data. We performed multilocus genetic clustering analyses and used multiple statistical methods to detect levels of hybridization. We tested hypotheses about habitat use between G. agassizii and G. morafkai in the region where they co-occur using habitat suitability models. Gopherus agassizii and G. morafkai maintain independent taxonomic identities likely due to ecological niche partitioning, and the maintenance of the hybrid zone is best described by a geographical selection gradient model.

  • mycoplasma agassizii in morafka s desert tortoise Gopherus morafkai in mexico
    Journal of Wildlife Diseases, 2015
    Co-Authors: Kristin H Berry, Mercy Vaughn, Mary B Brown, Timothy A Gowan, Mary Ann Hasskamp, Ma Cristina Melendez Torres
    Abstract:

    We conducted health evaluations of 69 wild and 22 captive Morafka's desert tortoises (Gopherus morafkai) in Mexico between 2005 and 2008. The wild tortoises were from 11 sites in the states of Sonora and Sinaloa, and the captive tortoises were from the state-managed Centro Ecologico de Sonora Zoo in Hermosillo and a private residence in the town of Alamos. We tested 88 tortoises for mycoplasmal upper respiratory tract disease (URTD) using enzyme-linked immunosorbent assays for specific antibody and by culture and PCR for detection of Mycoplasma agassizii and Mycoplasma testudineum. Fifteen of 22 captive tortoises had one or more positive diagnostic test results for M. agassizii whereas no wild tortoises had positive tests. Tortoises with positive tests also had significantly more moderate and severe clinical signs of mycoplasmosis on beaks and nares compared to tortoises with negative tests. Captive tortoises also exhibited significantly more clinical signs of illness than did wild tortoises, including lethargy and moderate to severe ocular signs. The severity of trauma and diseases of the shell and integument did not differ significantly among tortoises by site; however, clinical signs of moderate to severe trauma and disease were more prevalent in older tortoises. Similar to research findings for other species in the genus Gopherus in the US, we found that URTD is an important disease in captive tortoises. If they escape or are released by intention or accident to the wild, captive tortoises are likely to pose risks to healthy, naive wild populations.

  • Are captive tortoises a reservoir for conservation? An assessment of genealogical affiliation of captive Gopherus agassizii to local, wild populations
    Conservation Genetics, 2013
    Co-Authors: Taylor Edwards, Kristin H Berry
    Abstract:

    The conservation of tortoises poses a unique situation because several threatened species are commonly kept as pets within their native ranges. Thus, there is potential for captive populations to be a reservoir for repatriation efforts. We assess the utility of captive populations of the threatened Agassiz’s desert tortoise (Gopherus agassizii) for recovery efforts based on genetic affinity to local areas. We collected samples from 130 captive desert tortoises from three desert communities: two in California (Ridgecrest and Joshua Tree) and the Desert Tortoise Conservation Center (Las Vegas) in Nevada. We tested all samples for 25 short tandem repeats and sequenced 1,109 bp of the mitochondrial genome. We compared captive genotypes to a database of 1,258 Gopherus samples, including 657 wild caught G. agassizii spanning the full range of the species. We conducted population assignment tests to determine the genetic origins of the captive individuals. For our total sample set, only 44 % of captive individuals were assigned to local populations based on genetic units derived from the reference database. One individual from Joshua Tree, California, was identified as being a Morafka’s desert tortoise, G. morafkai, a cryptic species which is not native to the Mojave Desert. Our data suggest that captive desert tortoises kept within the native range of G. agassizii cannot be presumed to have a genealogical affiliation to wild tortoises in their geographic proximity. Precautions should be taken before considering the release of captive tortoises into the wild as a management tool for recovery.

  • the dazed and confused identity of agassiz s land tortoise Gopherus agassizii testudines testudinidae with the description of a new species and its consequences for conservation
    ZooKeys, 2011
    Co-Authors: Robert W Murphy, Kristin H Berry, Taylor Edwards, Alan E Leviton, Amy Lathrop, Daren J Riedle
    Abstract:

    We investigate a cornucopia of problems associated with the identity of the desert tortoise, Gopherus agassizii (Cooper). The date of publication is found to be 1861, rather than 1863. Only one of the three original cotypes exists, and it is designated as the lectotype of the species. Another cotype is found to have been destroyed in the 1906 San Francisco earthquake and subsequent fire. The third is lost. The lectotype is genetically confirmed to be from California, and not Arizona, USA as sometimes reported. Maternally, the holotype of Gopherus lepidocephalus (Ottley & Velazques Solis. 1989) from the Cape Region of Baja California Sur, Mexico is also from the Mojavian population of the desert tortoise, and not from Tiburon Island, Sonora, Mexico as previously proposed. A suite of characters serve to diagnose tortoises west and north of the Colorado River, the Mojavian population, from those east and south of the river in Arizona, USA, and Sonora and Sinaloa, Mexico, the Sonoran population. Species recognition is warranted and because Gopherus lepidocephalus is from the Mojavian population, no names are available for the Sonoran species. Thus, a new species, Gopherus morafkaisp. n., is named and this action reduces the distribution of Gopherus agassizii to only 30% of its former range. This reduction has important implications for the conservation and protection of Gopherus agassizii, which may deserve a higher level of protection.

Kenro Kusumi - One of the best experts on this subject based on the ideXlab platform.

Robert W Murphy - One of the best experts on this subject based on the ideXlab platform.

Brian T. Henen - One of the best experts on this subject based on the ideXlab platform.

  • Reproductive Ecology and Life History of Female Sonoran Desert Tortoises (Gopherus morafkai)
    Herpetological Monographs, 2018
    Co-Authors: Roy C. Averill-murray, Terry E. Christopher, Brian T. Henen
    Abstract:

    Abstract We studied female Gopherus morafkai reproduction for 10 yr to evaluate reproductive variation and environmental factors that influenced reproduction. In contrast to vitellogenesis in other Gopherus, substantial follicle growth occurred during the spring after emergence from hibernation. Vitellogenesis and egg production varied considerably among individuals. The smallest egg-producing female had a carapace length of 220 mm, and no female produced more than one clutch per year. Compared to small females, large females were more likely to reproduce in a given year and produced larger eggs, but body size did not affect clutch size. Good maternal body condition contributed to follicle growth in winter, larger clutches, and larger eggs in a clutch. Females that emerged from hibernation earlier were more likely to produce eggs. Early-emerging females also produced larger eggs than did females that emerged later. These reproductive traits contribute to a life history that resembles an income breeder com...

  • the agassiz s desert tortoise genome provides a resource for the conservation of a threatened species
    PLOS ONE, 2017
    Co-Authors: Marc Tollis, Taylor Edwards, Greer A. Dolby, John A Cornelius, Alice E Karl, Brian T. Henen, Dale F Denardo, Robert W Murphy, Kenro Kusumi
    Abstract:

    Agassiz’s desert tortoise (Gopherus agassizii) is a long-lived species native to the Mojave Desert and is listed as threatened under the US Endangered Species Act. To aid conservation efforts for preserving the genetic diversity of this species, we generated a whole genome reference sequence with an annotation based on deep transcriptome sequences of adult skeletal muscle, lung, brain, and blood. The draft genome assembly for G. agassizii has a scaffold N50 length of 252 kbp and a total length of 2.4 Gbp. Genome annotation reveals 20,172 protein-coding genes in the G. agassizii assembly, and that gene structure is more similar to chicken than other turtles. We provide a series of comparative analyses demonstrating (1) that turtles are among the slowest-evolving genome-enabled reptiles, (2) amino acid changes in genes controlling desert tortoise traits such as shell development, longevity and osmoregulation, and (3) fixed variants across the Gopherus species complex in genes related to desert adaptations, including circadian rhythm and innate immune response. This G. agassizii genome reference and annotation is the first such resource for any tortoise, and will serve as a foundation for future analysis of the genetic basis of adaptations to the desert environment, allow for investigation into genomic factors affecting tortoise health, disease and longevity, and serve as a valuable resource for additional studies in this species complex.

  • Assembly statistics for the genome of Gopherus agassizii.
    2017
    Co-Authors: Marc Tollis, Taylor Edwards, Greer A. Dolby, John A Cornelius, Alice E Karl, Brian T. Henen, Dale F Denardo, Robert W Murphy, Kenro Kusumi
    Abstract:

    Assembly statistics for the genome of Gopherus agassizii.

  • Sequences used for the assembly of the Agassiz’s desert tortoise (Gopherus agassizii) genome.
    2017
    Co-Authors: Marc Tollis, Taylor Edwards, Greer A. Dolby, John A Cornelius, Alice E Karl, Brian T. Henen, Dale F Denardo, Robert W Murphy, Kenro Kusumi
    Abstract:

    Sequences used for the assembly of the Agassiz’s desert tortoise (Gopherus agassizii) genome.

  • Genes under accelerated evolution across chelonians and genes with fixed differences between species in the Gopherus desert tortoise species complex according to this study.
    2017
    Co-Authors: Marc Tollis, Taylor Edwards, Greer A. Dolby, John A Cornelius, Alice E Karl, Brian T. Henen, Dale F Denardo, Robert W Murphy, Kenro Kusumi
    Abstract:

    Genes under accelerated evolution across chelonians and genes with fixed differences between species in the Gopherus desert tortoise species complex according to this study.

Related terms

Gopherus - 15 days free trial to Access Experts & Abstracts