Batrachochytrium salamandrivorans | |
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Bsal infection in the skin of a fire salamander | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Chytridiomycota |
Class: | Chytridiomycetes |
Order: | Rhizophydiales |
Family: | Batrachochytriaceae |
Genus: | Batrachochytrium |
Species: | B. salamandrivorans |
Binomial name | |
Batrachochytrium salamandrivorans Martel A., Blooi M., Bossuyt F., Pasmans F. (2013) [1] | |
Batrachochytrium salamandrivorans (Bsal) is a pathogenic chytrid fungus that infects amphibian species. Although salamanders and newts seem to be the most susceptible, some anuran species are also affected. Bsal has emerged recently and poses a major threat to species in Europe and North America.
It was described in 2013 based on a strain collected from skin tissue of fire salamanders Salamandra salamandra . The pathogen, unidentified up to then, had devastated fire salamander populations in the Netherlands. Molecular phylogenetics confirmed it as related to the well known chytrid B. dendrobatidis . Like this species, it causes chytridiomycosis, which is manifested in skin lesions and is lethal for the salamanders. [1] Damage to the epidermal layer can be extensive and may result in osmoregulatory [2] issues or sepsis. [3]
Another study estimated that this species had diverged from B. dendrobatidis in the Late Cretaceous or early Paleogene. While initial susceptibility testing showed frogs and caecilians seemed to be resistant to Bsal infection, it was lethal to many European and some North American salamanders. East Asian salamanders were susceptible but able to tolerate infections. The fungus was also detected in a more-than-150-year-old museum specimen of the Japanese sword-tailed newt. This suggests it had originally emerged and co-evolved with salamanders in East Asia, forming its natural reservoir, and was introduced to Europe rather recently through the trade of species such as the fire belly newts as pets. [4] The asian origin hypothesis for Bsal is supported by additional studies which have found Bsal in wild urodela populations in Asia and in animals of asian origin being transported via the pet trade. [5] [6] [7] Since the pathogens initial discovery, it has been found in several additional areas across Europe in both wild and captive populations. One study was able to detect Bsal in 7 of 11 captive urodele collections. [8]
The description of this pathogen and its aggressiveness raised concern in the scientific community and the public, fearing that it might be a rising threat to Western hemisphere salamanders. [9] [10] On January 12, 2016, the U.S. government issued a directive that prohibited the importation of salamanders in order to reduce the threat posed by B. salamandrivorans. [11]
Batrachochytrium is derived from the Greek words batrachos, "frog", and chytra, "earthen pot" (describing the structure that contains unreleased zoospores); salamandrivorans is from the Greek salamandra, "salamander", and Latin vorans, "eating", which refers to extensive skin destruction and rapid death in infected salamanders. [12]
The most comprehensive Bsal species susceptibility performed to date has been by Martel et al 2014. [4] Their experiments demonstrated Bsal susceptibility followed a phylogenetic trend with many Salamandridae species being lethally susceptible. Recent work has demonstrated that some lungless species, specifically those in the Spelerpini tribe might also be clinically susceptible to Bsal [13]
Bsal is a serious threat to salamander species, while it has not yet been confirmed in North America, [14] Bsal has had catastrophic effects on certain European salamander populations, believed to be the cause of a 96% decline in populations with in the Netherlands. [15] More than a third of the worlds salamanders live in the United States, [16] and 40% of those salamanders are already threatened. [17] While regulations on the most likely avenue of introduction into North America, amphibian trade, [18] are in place in both Canada and the United States, regulations are seriously lacking in Mexico. Furthermore, Bsal has the potential to infect an estimated 80 to 140 North American salamander species. [19]
This section includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations .(January 2024) |
This section includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations .(January 2024) |
This section includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations .(January 2024) |
More information on Bsal and other diseases impacting amphibian populations, including Batrachochytrium dendrobatidis and Ranavirus can be found at the Southeast Partners in Amphibian and Reptile Conservation disease task team web-page.
Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek χυτρίδιον (khutrídion), meaning "little pot", describing the structure containing unreleased zoospores. Chytrids are one of the earliest diverging fungal lineages, and their membership in kingdom Fungi is demonstrated with chitin cell walls, a posterior whiplash flagellum, absorptive nutrition, use of glycogen as an energy storage compound, and synthesis of lysine by the α-amino adipic acid (AAA) pathway.
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The eastern newt is a common newt of eastern North America. It frequents small lakes, ponds, and streams or nearby wet forests. The eastern newt produces tetrodotoxin, which makes the species unpalatable to predatory fish and crayfish. It has a lifespan of 12 to 15 years in the wild, and it may grow to 5 in (13 cm) in length. These animals are common aquarium pets, being either collected from the wild or sold commercially. The striking bright orange juvenile stage, which is land-dwelling, is known as a red eft. Some sources blend the general name of the species and that of the red-spotted newt subspecies into the eastern red-spotted newt.
Chytridiomycosis is an infectious disease in amphibians, caused by the chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans. Chytridiomycosis has been linked to dramatic population declines or extinctions of amphibian species in western North America, Central America, South America, eastern Australia, east Africa (Tanzania), and Dominica and Montserrat in the Caribbean. Much of the New World is also at risk of the disease arriving within the coming years. The fungus is capable of causing sporadic deaths in some amphibian populations and 100% mortality in others. No effective measure is known for control of the disease in wild populations. Various clinical signs are seen by individuals affected by the disease. A number of options are possible for controlling this disease-causing fungus, though none has proved to be feasible on a large scale. The disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30% of the amphibian species of the world. Some research found evidence insufficient for linking chytrid fungi and chytridiomycosis to global amphibian declines, but more recent research establishes a connection and attributes the spread of the disease to its transmission through international trade routes into native ecosystems.
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Karen R. Lips is a Professor of Biology at University of Maryland, College Park. Lips' work in the 1990s eventually contributed to the identification of the chytrid fungus as the primary cause of frog decline worldwide.
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Jessica Hua is an associate professor in the Department of Biological Sciences at Binghamton University, NY. In addition Hua is the Director for the Center for Integrated Watershed Studies at Binghamton University which focuses on understanding watersheds and the human influences on them through research. She is a herpetologist and oversees her own lab, The Hua Lab, where they focus on ecological interactions, evolutionary processes and ecological-evolutionary feedbacks. Hua's background has led to her appreciation of education with coming from a refugee family who "epitomizes the concept of the American Dream". Her research aims to help others gain opportunities while also establishing a lab that is inclusive and diverse. Hua also enjoys a variety of sports and plays disc golf professionally since 2016.