The Dangerous Fungus That Affects Salamanders
Salamanders have specific fungi that cause fairly serious, even fatal, infections. This is the case of a recent discovery, that of the Batrachochytrium salamandrivorans mushroom . This mycosis was first described in April 2018. It has affected several species of salamanders across the European continent, both wild and domestic.
Salamanders Have Mushrooms: An Overview
The fungus Batrachochytrium salamandrivorans was first identified in 2013, when a drastic decrease in the number of salamanders was detected in the Netherlands.
Since then, this fungus has ravaged amphibian populations in this country and others on the European continent. In fact, it has been found in numerous regions bordering Belgium and in some captive salamanders and newts in Germany and the UK.
The native species of B. salamandrivoran s are thought to come from Southeast Asia, particularly Japan, Thailand, Vietnam and, recently, China.
Outside of Western Europe, B. salamandrivorans is known to infect a number of native newt species in Asia, but it does not appear to be a significant cause of disease or mortality in these species. This is why it is considered endemic to Asia and the species in that region could act as a reservoir for disease.
Transmission of the virus
This fungus proliferates in humid environments, both in fresh and salty or brackish waters. Transmission is usually horizontal, by direct contact with contaminated water, since the fungus remains unchanged in the environment, in its resistant form: the spores. The spores actively swim in the water; drying is fatal for them at all stages of their life cycle.
The risk factors that favor infection are temperatures around 15 ° C. In fact, B. salamandrivorans has been shown not to colonize the skin of salamanders at temperatures above 25 ° C. Specimens that survive the disease can be persistently infected.
Symptoms
It causes chithridiomycosis, characterized by lesions – in this case fatal – on the skin. The fungus is a parasite of the cells of the epidermis. It causes ulcers with significant skin degradation and demeans the animal causing its death within two to three weeks.
In general, the clinical symptoms of disease caused by fungi of the genus Batrachochytrium are variable and do not allow a certain diagnosis.
Salamanders have mushrooms
Social, economic and environmental importance
Amphibians are one of the most important animal groups in the world. They provide a series of “services”, such as:
- Medicines derived from the secretions of substances present on their skin.
- They control the action of insects, pests, etc.
- On a cultural level, the salamander is an important animal on an aesthetic, religious or spiritual level.
- Salamanders contribute to the functioning of ecosystems, thanks to their role in the food chain.
Control instruments
A protocol has been developed for the treatment of infected salamanders. Infection resolves in infected salamanders exposed to a temperature of 25 ° C for 10 days. However, the margin between the temperature capable of eliminating the fungus and the upper critical temperature tolerated by most of these animals is very narrow.
Another effective treatment is the administration of a combination of antibiotics, a method reserved exclusively for animals kept in captivity.
Antibiotic treatments for salamanders that have fungi
In order to stem the invasion of the pathogen, movement restrictions must be implemented to limit its introduction, as well as early detection measures through surveillance of high-risk areas.
The illegal trade in salamanders is considered the most likely route for B. salamandrivorans to enter new geographic regions.
