Time filter

Source Type

Memphis, TN, United States

Calatayud N.E.,Mississippi State University | Langhorne C.J.,Mississippi State University | Mullen A.C.,Mississippi State University | Williams C.L.,Mississippi State University | And 4 more authors.
Theriogenology | Year: 2015

Declines of the southern Rocky Mountain population of boreal toad (Anaxyrus boreas boreas) have led to the establishment of a captive assurance population and reintroduction program, in an attempt to preserve and propagate this geographically isolated population. One of the unique adaptations of this species is its ability to survive in cold environments by undergoing long periods of hibernation. In captivity, hibernation can be avoided altogether, decreasing morbidity caused by compromised immune systems. However, it is not entirely clear how essential hibernation is to reproductive success. In this study, the effects of hibernation versus nonhibernation, and exogenous hormones on oviposition, were examined in boreal toad females in the absence of males. In the summers of 2011 and 2012, 20 females housed at Mississippi State University were treated with a double priming dose of hCG and various ovulatory doses of hCG and LH-releasing hormone analog but denied hibernation. Exogenous hormones, in the absence of hibernation, could not induce oviposition over two breeding seasons (2011-2012). In contrast, during the summer of 2012 and 2013, 17 of 22 females (77%) housed at the Native Aquatic Species Restoration Facility (Alamosa, CO, USA) oviposited after they were treated with two priming doses of hCG (3.7 IU/g each) and a single ovulation dose of hCG (13.5 IU/g) and LH-releasing hormone analog (0.4μg/g) after hibernation. There was a significant difference in oviposition between females that were hibernated and received hormones (2012, P<0.05 and 2013, P<0.01) compared to hibernated control females. In 2013, 12 of 16 remaining Mississippi State University females from the same group used in 2011 and 2012 were hibernated for 1, 3, and 6months, respectively and then treated with the same hormone regimen administered to females at the Native Aquatic Species Restoration Facility. Together, hibernation and hormone treatments significantly increased oviposition (P<0.05), with 33% of females ovipositing. These results suggest that (1) hibernation is a key factor influencing oviposition that cannot be exclusively circumvented by exogenous hormones; (2) females do not require the presence of a male to oviposit after hormone treatments; and (3) longer hibernation periods are not beneficial for oviposition. The hormonal induction of oviposition in the absence of males and shorter hibernation periods could have important captive management implications for the boreal toad. Furthermore, the production of viable offspring by IVF where natural mating is limited could become an important tool for genetic management of this boreal toad captive population. © 2015 Elsevier Inc.

Clulow J.,University of Newcastle | Trudeau V.L.,University of Ottawa | Kouba A.J.,Memphis Zoo
Advances in Experimental Medicine and Biology | Year: 2014

Each amphibian species is evolutionarily distinct, having developed highly specialized and diverse reproductive strategies in both terrestrial and aquatic environments. These unique reproductive patterns and mechanisms, key to species propagation, have only been explored in a limited number of laboratory models. Although the development of applied reproductive technologies for amphibians has proven useful for a few threatened species, the real benefit of this technology has been new insights into the reproductive adaptations, behavior, endocrinology, and physiological mechanisms that have evolved over millions of years. As the basic fundamental database on amphibian reproductive physiology has grown, so has the applied benefit for species conservation. In particular, technologies such as non-invasive fecal and urinary hormone assays, hormone treatments for induced breeding or gamete collection, in vitro fertilization, and the ability to establish genome resource banks have all played important roles in monitoring or managing small populations of captive species. Amphibians have the ability to produce a large excess of germplasm (up to 10,000 ovulated eggs in a single reproductive event) that if not collected and preserved, would represent a wasted valuable resource. We discuss the current state of knowledge in assisted reproductive technologies for amphibians and why their extinction crisis means these available tools can no longer be implemented as small-scale, last-ditch efforts. The reproductive technologies must be established early as a key component of large-scale species recovery. © Springer Science+Business Media New York 2014.

Swaisgood R.R.,San Diego Zoos Institute for Conservation Research | Wei F.,CAS Institute of Zoology | Mcshea W.J.,Conservation and Research Center | Wildt D.E.,Conservation and Research Center | And 4 more authors.
Integrative Zoology | Year: 2011

The giant panda (Ailuropoda melanoleuca David, 1869) is an iconic species for global conservation, yet field research has only recently advanced to the point where adaptive management is possible Here, we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation forward. Because of scientific, funding, political, and logistical hurdles, few endangered species management programs have embraced adaptive management, wherein management decisions are shaped iteratively by targeted scientific research. Specific threats, such as habitat destruction, anthropogenic disturbance and fragmented nonviable populations, need to be addressed simultaneously by researchers, managers and policy-makers working in concert to understand and overcome these obstacles to species recovery. With the backing of the Chinese Government and the conservation community, the giant panda can become a high-profile test species for this much touted, but rarely implemented, approach to conservation management. © 2011 ISZS, Blackwell Publishing and IOZ/CAS.

Swaisgood R.R.,San Diego Zoos Institute for Conservation Research | Wei F.,CAS Institute of Zoology | Wildt D.E.,Conservation and Research Center | Kouba A.J.,Memphis Zoo | And 2 more authors.
Biology Letters | Year: 2010

The giant panda is a conservation icon, but science has been slow to take up its cause in earnest. In the past decade, researchers have been making up for lost time, as reflected in the flurry of activity reported at the symposium Conservation Science for Giant Pandas and Their Habitat at the 2009 International Congress for Conservation Biology (ICCB) in Beijing. In reports addressing topics ranging from spatial ecology to molecular censusing, from habitat recovery in newly established reserves to earthquake-induced habitat loss, from new insights into factors limiting carrying capacity to the uncertain effects of climate change, this symposium displayed the vibrant and blossoming application of science to giant panda conservation. Collectively, we find that we have come a long way, but we also reach an all-too-familiar conclusion: the more we know, the more challenges are revealed. While many earlier findings are supported, many of our assumptions are debatable. Here we discuss recent advancements in conservation science for giant pandas and suggest that the way forward is more direct application of emerging science to management and policy. © 2010 The Royal Society.

Kouba A.J.,Memphis Zoo | Lloyd R.E.,University of Portsmouth | Houck M.L.,Institute for Conservation Research | Silla A.J.,University of Wollongong | And 10 more authors.
Biological Conservation | Year: 2013

How to conserve our planet's rapidly disappearing biodiversity is one of the greatest challenges of our generation. Among terrestrial vertebrate taxa, amphibians are most at risk with 41% of all known species experiencing population declines and one-third threatened with extinction. Although many institutions have responded by establishing captive assurance colonies for several critically endangered amphibians, the resources provided by these conservation organizations will not be enough to save all species 'at risk' without a multi-pronged approach. Around the world, zoos, aquariums, governments, and conservation NGOs are beginning to establish amphibian gene banks to conserve, in perpetuity, the remaining extant genetic diversity for many of these critically endangered species. A suite of biomaterials has been targeted for cryoconservation including blood, cell cultures, tissues, spermatozoa, eggs, and embryos. Several international workshops on amphibian gene banking and assisted reproductive technologies have been held between 2010 and 2012, bringing together leading experts in the fields of amphibian ecology, physiology, and cryobiology to synthesize emerging trends for biobanking amphibian genetic resources, provide opportunities for collaboration, and discuss future research directions. The following review paper and summary will provide a synopsis of these international workshops, in particular the hopes, realities, and current challenges inherent to this applied research field. © 2013 Elsevier Ltd.

Discover hidden collaborations