That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information
As mentioned in Part I of this article, tiger salamander larvae (Ambystoma tigrinum), run through with a hook while alive, are still used as fishing bait in some parts of the USA. Last time we learned about the bait trade’s role in spreading a Chitrid fungus that is decimating amphibian populations worldwide, and in hastening the extinction of endangered tiger salamanders through hybridization.
Endangered but Legally Exploited
Despite the aforementioned environmental nightmares, the bait trade in tiger salamanders remains largely unregulated, resulting in infected animals being shipped from state to state. This practice hastens the spread of already fast-moving pathogens and of non-native salamanders, as surveys have revealed that most people and bait shops release unused larvae into local waterways.
The situation is rendered all the more bizarre by the fact that these largest of all terrestrial salamanders are critically endangered in many areas. In fact, several subspecies, including the Eastern tiger salamander (Ambystoma tigrinum tigrinum), are protected by individual states as endangered species!
Other Threats
Tiger salamanders also face serious threats from habitat loss, pollution and the introduction of game fish to breeding ponds. Their use of two distinct habitats – aquatic and terrestrial – renders them especially vulnerable.
Protection, when offered, is often ineffective. In New York State, for example, 75 feet of land around breeding ponds is closed to development – but research has shown that few if any adults live within that radius!
Tiger Salamanders in Captivity
Tiger salamanders make interesting and unusually responsive captives. Longevities exceed 30 years, but captive reproduction is still somewhat problematical. They certainly deserve more attention from hobbyists …please write in for further information.
American Bullfrogs
American bullfrogs (Rana/Lithobates catesbeianus) have also recently been implicated in spreading amphibian diseases (New Scientist: May, 2009). Researchers monitoring food markets in NYC and California discovered that 8% of the frogs being offered for sale carried ranavirus and nearly 70% were infected with Chytrid!
Further Reading
You can learn about the natural history of the eastern tiger salamander, and the steps being taken by the NYS DEC to prevent its extinction, at
http://www.dec.ny.gov/animals/7143.html.
The Organization Amphibian Ark has taken a leading role in Chytrid research. Read about how this fungus has caused amphibian extinctions, and predictions for the future of the epidemic, at http://www.amphibianark.org/chytrid.htm.
Image referenced from Wikipedia and originally posted by Tigershrike.
Very interesting post Frank, Ive heard the taxonomy of the salamanders is starting to become confusing because the bait is dumped and the larvae metamorphose into adults, what’s your take on the situation?
Hello Ryan,
Thanks you. There’s some evidence that barred tiger salamanders (Ambystoma mavortium), which are used as bait, have been hybridizing with the endangered California tiger salamander (A. californiense): I’ve not read anything other than the original article describing the occurrence, but I’ll look into it a bit more; please let me know if you find anything also. Best, Frank