/pdf/ranaviruses-lethal-pathogens-of-ectothermic-vertebrates-1wkphwer0t.pdf

Ranaviruses: Lethal Pathogens of Ectothermic Vertebrates

Recognizing the pathological changes caused by ranaviruses, understanding how to properly collect test samples, and knowing what diagnostic tools to choose are key to detecting ranaviruses and in determining whether they are a factor in morbidity and mortality events. Whether infection occurs in fish, reptiles, or amphibians, clinical disease is typically acute and can affect a high proportion of the population. Among ectothermic vertebrates, affected individuals can present with hemorrhages, edema, and necrosis. Generally, microscopic examination reveals intracytoplasmic inclusion bodies and necrosis of hematopoietic tissues, vascular endothelium, and epithelial cells. Ultimately, the type and severity of the lesions that develop vary depending upon the host species, type of ranavirus, or environmental factors. Our ability to identify lesions caused by ranaviruses is improving because of the knowledge gained from laboratory experiments and the improvement of existing, or development of new diagnostic tests. There is no single Gold Standard test for ranavirus detection, rather the diagnostic test chosen depends on the question asked. For example, a surveillance study may use quantitative real-time PCR (qPCR) to detect ranaviruses, but an investigation of a mortality event may use virus isolation, qPCR, histopathology, electron microscopy, and bioassay. To date, a treatment for ranavirus infections has not been found; however, vaccine development against iridoviruses is showing promise for both DNA and live vaccines within the aquaculture industry.

/pdf/comparative-pathology-of-ranaviruses-and-diagnostic-2qi80az5hz.pdf

Comparative Pathology of Ranaviruses and Diagnostic Techniques

Translocation of species to new locations is a widespread procedure in conservationbiology Conventional wisdom suggests using large numbers of donor stockfrom sites as close and as ecologically similar to the recipient location as possibleto minimise risks from maladaptation and outbreeding depression Here, wecompare translocation success to a common receptor site of animals from a largebut distant population with those from smaller proximal populations Commontoads (Bufo bufo) from a site far from the recipient locality and with very differenthabitat rapidly established a new population where three attempts with localanimals failed After 10 years, the new population retained allele frequency distributionsat microsatellite loci almost the same as the donor site, whereas majorhistocompatibility complex allele frequencies changed to resemble local onesVariations in phenology and climate could not readily explain the success of thedistant translocation source We postulate that success was due to the very largesize of the donor population compared with local sources, implying that highlevels of mean fitness or adaptive variation can be more important than localfactors when considering translocations, at least in some circumstances

Donor population size rather than local adaptation can be a key determinant of amphibian translocation success

Many features of the urban environment, such as a warmer microclimate, can positively affect populations of birds and mammals inhabiting cities, while at the same time may affect amphibians negativ...

https://www.tandfonline.com/doi/pdf/10.1080/24750263.2020.1744743

Two amphibian species in the urban environment: changes in the occurrence, spawning phenology and adult condition of common and green toads

Amfibi ve surungenlerin kis mevsimi boyunca yasayabilmek icin olumsuz hava kosullarina toprak altinda bir siginak arayarak yanit verdigi bir gercektir. Mevcut literatur, bazi surungen ve amfibi turlerinin bilinen hibernasyon donemlerinden once ozellikle de dusuk rakimlarda aktif olabildigini gostermistir. Bu calismada, yuksek rakimda degisen hava kosullarinin ayni habitatlari paylasan bazi amfibi ve surungen turleri uzerinde benzer etkilere neden olabilecegini rapor ettik. Bu calismada Lacerta media , Bufo bufo ve Rana macrocnemis 'in erken aktivitesi Turkiye’nin Gumushane ilinde rapor edilmistir. Bazi amfibi ve surungen turlerinde bilinen kis uykusu donemlerinden onceki aktivitelerinin nedenlerinden birisi soz konusu turlerin degisen sicakliklara karsi cok hassas olmalari olabilir. Kuresel isinmanin amfibiler ve surungenler uzerindeki etkileri acikca gorulmektedir ve kis aylarinda aktif olabilirler. Bu durum akla, L. media , B. bufo ve R. macrocnemis 'in hava sicakliklari izin verdigi surece aktif olabileceklerini getirmektedir.

/pdf/early-waking-from-hibernation-in-some-amphibian-and-reptile-2i2y2ioakb.pdf

Early waking from hibernation in some amphibian and reptile species from Gümüşhane Province of Turkey

Many species of amphibians have bred in a Woodingdean garden pond for more than 30 years. In summer 2007 an outbreak of Ranavirus occurred and this paper describes its impact on three species of anurans living wild in the garden and two species kept in an outdoor vivarium. Common frog Rana temporaria numbers were reduced by >80%. Common toads Bufo bufo decreased by perhaps 20% whereas pool frogs Pelophylax lessonae were scarcely affected. A single natterjack B. calamita died in the vivarium where at least five survived, but all midwife toads Alytes obstetricans (adults and larvae) in the same enclosure perished. There was no sign of recovery of the common frog population over the ensuing five years.

Impact of Ranavirus on garden amphibian populations

Common toads Bufo bufo have declined over much of southern and eastern England in recent decades where other widespread amphibian species have remained relatively stable. One such toad decline, at Offham marshes in Sussex, was investigated over the fifteen year period 1998-2012 immediately subsequent to a tenfold decrease in population size between 1989 and 1997. Syntopic amphibians (Rana temporaria, Lissotriton vulgaris and L. helveticus) probably also declined at this site. The surviving toad population continued to recruit new cohorts and had an apparently healthy age structure. Habitat quality (aquatic and terrestrial) remained good and there was no evidence of disease. An invasive species (Pelophylax ridibundus) was excluded as a likely cause of toad decline. However, traffic on a neighbouring road rendered more than half the previously available terrestrial habitat for toads essentially unreachable. Furthermore, reduced management of vegetation in ditches where the toads breed apparently increased mortality of developing tadpoles. Future prospects for conserving and increasing the toad population are discussed.

/pdf/decline-and-flounder-of-a-sussex-common-toad-bufo-bufo-1avh2z0chd.pdf

Reptile Conservation

Papers

Impact of Ranavirus on garden amphibian populations

Decline and flounder of a Sussex common toad (Bufo bufo) population