Once thought to be born from flames this week we’re looking at the fire salamander. These black and yellow amphibians are found across continental Europe and are famed for their colouration.
Taxonomy and Evolution
Fire salamanders have the easy to remember name of Salamandra salamandra and is closely related to other salamanders including the alpine salamander. This genus has been very long lived with it first appearing in the fossil record during the Paleocene epoch, 66 to 55 million years ago. As expected, the genus Salamandra belongs to the salamander family which appeared 89 million years ago during the Cretaceous. There are several subspecies of fire salamander, although in recent years some have been reclassified to be a species in their own right. Other than geographic range these subspecies can be distinguished by the spots on their bodies.
Biology and Behaviour
Fire salamanders are the largest salamanders found in Europe and are one of the largest members of the salamander family. On average they reach 15 to 20 centimetres in length and weight up to 19 grams. The most iconic thing about fire salamanders is their patterns, something which has made them popular in the pet trade. They are black with yellow spots and stripes, and depending on the subspecies these spots/stripes vary greatly. In some the patterns are an orange or red instead of yellow, and the Portuguese fire salamander is incredibly spotty. Females are slightly larger than males, but otherwise sexual dimorphism is negligible. For their small size they can live a long time with them exceeding 15 years in age, and one housed in the German Museum Koenig lived to be 50!
Unlike newts or frogs salamanders often mate on land, with most fire salamanders taking this approach. Fire salamanders reproduce with internal fertilisation, meaning the female does not lay eggs that the males then fertilise, and they have an interesting way to ensure that reproduction happens at the right time. Females can store sperm for a period of time before using it to fertilise her eggs, so this gives the female an opportunity to give birth when environmental conditions are the best. Fire salamanders do not lay eggs, instead they are viviparous so they retain the eggs in their body and give birth to live young. The young will survive on their egg yolk until they reach a certain level of maturity before being birthed. In most subspecies the mother will return to the water, ideally a still body of water, and give birth to larvae. Barely resembling the adults they have external feathery gills, are brown-grey, and have webbed toes for an aquatic life. They will spend their time eating and growing until they leave the water abandoning their gills, webbed toes, and paddle-like tail. In two subspecies, S.s. bernardezi and the yellow-striped fire salamander, they skip this entirely with the females giving birth to fully formed terrestrial salamanders.
Fire salamanders, like other amphibians, need access to the water or moist environments as they respire through pores in their skin. While they can respire with lungs diffusion through the skin helps them get enough oxygen. Nights are generally cooler and wetter so fire salamanders are often nocturnal, although they do come out during the day at times, and spend the day hiding in damp logs, leaf litter, and logs. They have large prominent eyes to aid in seeing in the dark giving them an advantage over predator and prey. Scientists have also found out that they rely on ‘landmarks’ in their habitat to help navigate showing how incredible their memory can be.
Toxins
Fire salamanders are incredibly toxic. The black and yellow colouration of the salamanders is used in nature as a warning to potential predators with it sending a clear message – ‘eat me and you’ll feel sorry’. The yellow spots and stripes contain parotid glands that secrete toxins called samandrin that are incredibly deadly. When threatened they can also spray these secretions at a potential predator which protects them at a distance. Samandrin affects the central nervous system and there is no antidote. Hyperventilation, muscle convulsions, dyspnea, and paralysis can be caused by samandrin, and in some animals, such as dogs, it can cause death.
Habitat and Distribution
Fire salamanders are found only in Europe, although some sources also mention North Africa and the Middle East. This is now inaccurate as the non-European populations have been reclassified as being their own species. They have an incredibly wide distribution regardless being found in Iberia, France, the Alps, southern Germany, Czechia, the Balkans, and Italy. Needing, ideally still, water to give birth fire salamanders are never found too far away from bodies of water. Their ideal habitat are cool forests and rocky outcrops with many being found in the mountains of the Alps. Due to their fondness for logs when medieval Europeans threw logs onto a fire the salamanders would come crawling out which sparked the belief that they might be born through fire. Before alchemy became a discredited science alchemists were fascinated by the salamander and, in what would turn out to be in vain, hoped to learn the secrets of fire from salamanders.
Diet and Predators
Fire salamanders are carnivorous throughout their life. Having a good sense of sight and smell they hunt through spotting or smelling prey, and they are somewhat active predators (being cold-blooded this does limit how active they can be). Worms, slugs, snails, flies, beetles, centipedes, millipedes, woodlice, and any invertebrate they can swallow whole is on the menu. Being so toxic adults have no active predators, but the larvae are not toxic. Dragonfly larvae, larger frogs and toads, crayfish, and fish can all hunt the salamander larvae. For this reason, females try and choose smaller bodies of water or still water as this reduces the chance of larger predators getting to the larvae, or being swept into places where predators will be. Even if a few get eaten, females give birth to an average of 80 larvae so many will potentially survive.
Conservation and Threats
The IUCN evaluated the fire salamander in 2022 and classified it as being ‘Least Concern’, but their numbers are decreasing. While many populations are doing well thanks to a successful conservation scheme implemented by the European Union has helped them. However, there are threats which have either wiped out or reduced the population in Spain, the Netherlands, Belgium, and Germany. The first is human encroachment into their habitats. Cutting down forests and destroying bodies of water that they rely on has reduced the available land where they can survive and separated populations. The pet trade, which the EU has tried to curtail, has also taken many healthy animals from the wild which could otherwise be helping the populations. This trade has also spread the deadly chytrid fungus to Europe. This fungus prevents amphibians from absorbing salts through their skin, prevents growth, causes ulcers, and behaviour changes which all leads to death. It has been spreading rapidly worldwide, aided by pet traders and rising global temperatures, and has already wiped out at least 99% of the fire salamanders in the Netherlands. While still common these factors could cause fire salamanders to become endangered.
Bibliography:
- Chris Mattison, (Ed.), Firefly Encyclopedia of Reptiles and Amphibians, Third Edition, (New York: Firefly Books, 2015)
- Chris Mattison, Nature Guide: Snakes and Other Reptiles and Amphibians, (New York: DK Publishing, 2014)
- Meredith Mahoney, Ann Chang, and Michelle Koo, ‘Salamandra salamandra‘, AmphibiaWeb, (19/10/2021), [Accessed 28/05/2023]
- Rose Sydlowski, ‘Fire Salamander’, Animal Diversity Web, (2000), [Accessed 28/05/2023]
- Edmund Brodie and Neal Smatresk, ‘The Antipredator Arsenal of Fire Salamanders: Spraying of Secretions from Highly Pressurized Dorsal Skin Glands’, Herpetologica, 46:1, (1990), 1-7
- ‘Common Fire Salamander’, IUCN, (20/08/2021), [Accessed 29/05/2023]
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