Exotic Amphibians Research Articles

Current snapshot of a highly invaded assemblage: Walter E. Meshaka Jr., Suzanne L. Collins, R. Bruce Bury, and Malcolm L. McCallum: Exotic amphibians and reptiles of the United States

Current snapshot of a highly invaded assemblage: Walter E. Meshaka Jr., Suzanne L. Collins, R. Bruce Bury, and Malcolm L. McCallum: Exotic amphibians and reptiles of the United States

A check list and population trends of invasive amphibians and reptiles in Taiwan.

Invasive species have impacted biodiversity all around the world. Among various ecosystems, islands are most vulnerable to these impacts due to their high ratio of endemism, highly specialized adaptation, and isolated and unique fauna. As with other subtropical islands, Taiwan faces constant risk of biological invasions and is currently ranked as one of the countries most affected by invasive amphibians and reptiles. In this paper, a comprehensive checklist of all known exotic amphibians and reptiles is provided, including twelve species which have successfully colonized Taiwan and six species with a controversial status. We provide an update on the knowledge of all these species including their distribution, colonization history, threats to native animals, and population trends based on literature records, fauna surveys, and data collected during invasive species eradication and control programs. A list of species with high invasive potentials is also provided. This study reports, for the first time, a comprehensive survey of invasive herpetofauna in Taiwan, which should provide a valuable reference to other regions which might suffer from similar invasion risk.

Cryptic invasion of Italian pool frogs (Pelophylax bergeri) across Western Europe unraveled by multilocus phylogeography

Human introductions of exotic amphibians can have catastrophic effects on native species. However, they usually remain unnoticed without genetic tools when species are difficult to distinguish morphologically. In Western Europe, pool frogs (Pelophylax sp.) make a worrisome case: recent genetic data showed the presence of Italian (Pelophylax bergeri) mtDNA haplotypes within the range of the threatened European Pelophylax lessonae, two morphologically similar taxa. Here we conduct a multilocus phylogeographic and population genetic survey of European and Italian pool frogs (combining present and historic samples), to investigate the origin(s) and consequences of potential introductions. Results are unequivocal: we show that the alien P. bergeri have extensively invaded France and north-Alpine Switzerland, and have also deeply introgressed with P. lessonae, which has led to the complete replacement of most populations. Alien specimens have probably been translocated multiple times from Central Italy at least prior to the 1960s. Based on our dense sampling, only two areas, north and south of the Alps still host native pool frogs in Switzerland, the Joux Valley near the French border and the canton of Ticino, respectively. Importantly, we show that these last P. lessonae populations are remnants of a private genetic diversity specific to Western Europe, which vanished during the P. bergeri’s invasion. Our study emphasizes the risk of genetic pollution during invasion by human-introduced taxa and brings alarming concern regarding uncontrolled amphibian translocations. Moreover, it demonstrates the necessity for genetic surveys to detect and monitor these invasions, especially where species determination is problematic.

Establishment risk and potential invasiveness of the selected exotic amphibians from pet trade in the European Union

The pet trade has grown in recent years and become the most important pathway for the introduction of non-indigenous species of amphibians and reptiles worldwide. Amphibians traded on the pet market have been widely overlooked in systematic invasion studies, so their establishment potential and invasion dynamics remain poorly understood, despite the fact that the impact of invaders from this taxonomic group on native biota may be considerable. The determination of the most common species of amphibians traded as pets was based on a survey of the market in the Czech Republic, which is an export hub for ornamental aquatic animals into the European Union (EU). Subsequently, the establishment potential of the most common species for EU was determined using a proven risk assessment model. Amphibians that scored higher than the established species Xenopus laevis were additionally evaluated for their invasion potential using the Amphibian Invasiveness Screening Kit (AmphISK).Sixteen species of amphibians in pet market (14 Anura, 2Caudata) have an establishment potential in the EU. However, none of these species have reached the invasion potential score of already spreading species X. laevis and Lithobates catesbeianus. The species closest to the threshold value were Lithobates pipiens and Pelophylax saharicus. Amphibians represent a rather small group within all traded animals but this fact should not lead us to an underestimation of their potential invasiveness.

Presence and prevalence of Batrachochytrium dendrobatidis in commercial amphibians in Mexico City.

In Mexico City, native and exotic amphibians are commonly sold through the pet trade. This study investigates the presence of Batrachochytrium dendrobatidis (Bd) in native amphibians being sold at two commercial markets and at a herpetarium in Mexico City. A total of 238 individuals (6 genera and 12 species) were tested for Bd using real-time polymerase chain reaction (PCR) analysis. There were 197 Bd-positive individuals (prevalence 82%) from five species of amphibians. Hyla eximia from the markets had very high Bd prevalence (100%; 76/76 and 99%; 88/89) but those from the herpetarium were Bd negative (0/12). Ambystoma mexicanum from the herpetarium also had a high Bd-positive prevalence (80%; 28/35). Though A. mexicanum is nearly extinct in the wild, a commercial market continues to flourish through the pet trade. Now that captive colonies of A. mexicanum are currently used for reintroduction programs, the authors recommend quarantine to reduce spread of Bd via movement of infected animals in the trade and between colonies and via disposal of wastewater from captive collections.

Batrachochytrium dendrobatidis prevalence and haplotypes in domestic and imported pet amphibians in Japan.

The international trade in amphibians is believed to have increased the spread of Batrachochytrium dendrobatidis (Bd), the fungal pathogen responsible for chytridiomycosis, which has caused a rapid decline in amphibian populations worldwide. We surveyed amphibians imported into Japan and those held in captivity for a long period or bred in Japan to clarify the Bd infection status. Samples were taken from 820 individuals of 109 amphibian species between 2008 and 2011 and were analyzed by a nested-PCR assay. Bd prevalence in imported amphibians was 10.3% (58/561), while it was 6.9% (18/259) in those in private collections and commercially bred amphibians in Japan. We identified the genotypes of this fungus using partial DNA sequences of the internal transcribed spacer (ITS) region. Sequencing of PCR products of all 76 Bd-positive samples revealed 11 haplotypes of the Bd ITS region. Haplotype A (DNA Data Bank of Japan accession number AB435211) was found in 90% (52/58) of imported amphibians. The results show that Bd is currently entering Japan via the international trade in exotic amphibians as pets, suggesting that the trade has indeed played a major role in the spread of Bd.

Patterns of transport and introduction of exotic amphibians in Australia

AbstractAimResearch on amphibian invasions has largely focused on the likelihood of successful establishment, while analysis of the previous stages in the invasion pathway (transport and introduction) is scarce despite its critical importance. Here, we investigate the patterns of taxonomic and geographic non‐randomness as well as the factors affecting the transport and introduction of amphibians.LocationAustralia.MethodsWe compiled and analysed a database on the identity of transported and introduced amphibians. First, we tested for taxonomic (family level) and geographic non‐randomness by comparing transported and introduced species with all extant caudates and anurans. Second, we constructed models to examine the influence of different factors upon the probability of transport and introduction of amphibians in Australia.ResultsAmphibians were transported via two main pathways: trade (71 species) and stowaway (38 species). In addition, several species were transported through both pathways. Transported species represented a taxonomic and geographic non‐random sample of all extant amphibian species. Conversely, introduced species constituted a random sample of the transported amphibians. Regardless of the transport pathway, the probability of transport of amphibians increased with increasing extent of their native geographical range. A large number of native Australian species have been transported outside their naturally occurring ranges, representing over 65% of the introduced species. Introduction is strongly correlated with the transport pathway, that is, species transported through two pathways were more likely to be released or escape from captivity.Main conclusionsThe probability of amphibians being transported and introduced to, or within, Australia is critically affected by their availability to be captured, bred and housed in captivity. Management strategies to prevent the future introduction and establishment of new amphibians need to include the people involved in species trade, as well as continued vigilance by biosecurity and custom agencies.

The Exotic Amphibians and Reptiles of Florida

Book Review: The Exotic Amphibians and Reptiles of Florida, Walter E. Meshaka, Jr., Brian P. Butterfield, J. Brian Hauge. Krieger Publishing, Co., Malabar, FL (2004).

Book Review: The Exotic Amphibians and Reptiles of Florida, Walter E. Meshaka, Jr., Brian P. Butterfield, J. Brian Hauge

Book Review: The Exotic Amphibians and Reptiles of Florida, Walter E. Meshaka, Jr., Brian P. Butterfield, J. Brian Hauge. Krieger Publishing, Co., Malabar, FL (2004).

The exotic amphibians and reptiles of Florida

The exotic amphibians and reptiles of Florida

The Amphibia and Pisces in the First Edition of the Systema Naturae

There is yet another aspect of Angel's work that cannot be passed over in silence: his talent for drawing. His skill may be judged from the plates accompanying his works on fishes, those that illustrate Bocourt's Expedition to Mexico, or the little atlases of color plates of exotic amphibians, reptiles, and fishes. A careful and conscientious observer of morphological characters, Angel made a career of systematics. During the course of patient studies he acquired an indisputable competence that gave him an important place among the herpetologists of the world. The honorary titles, both French and foreign, that were bestowed upon him testify to this. All who were associated with him will preserve the memory of this unaffected man, even-tempered and cheerful; of this affable colleague, who placed without reservation his great knowledge at the disposal of all, always ready to give counsel or render a service. Let the memory of this worker be for us a lesson and an example.-J. GuIBm, Sous-Directeur du Laboratoire de Zoologie (Reptiles et Poissons) du Museum, Paris. [Translation, courtesy of D. DWIGHT DAVIS.]