Most salamanders reproduce by laying eggs. These eggs are typically laid in the water, and attached to twigs, grass, or other vegetation just slightly below the water’s surface. But how long do salamander eggs take to hatch?
Most salamander eggs will hatch in 3 to 6 weeks, depending on the species, water temperature, and other environmental conditions. However, the eggs of some species can up to 4 months to hatch.
In general, salamander eggs will develop and hatch faster in warmer temperatures and slower in colder temperatures.
Other factors that can affect embryonic development rates include the water depth and water pH level.
How Long the Eggs of 20 Salamander Species Take to Hatch
The eggs laid by most salamander species will hatch after about three to six weeks. However, this will vary depending on the specific species, and the environmental conditions.
Some salamander eggs may hatch after only a week, while others may take up to two months before they hatch.
| Salamander Species | Scientific Name | How Long Their Eggs Take To Hatch |
| Tiger salamander | Ambystoma tigrinum | 19 – 50 days |
| Spotted salamander | Ambystoma maculatum | 20 – 60 days |
| Blue-spotted salamander | Ambystoma laterale | 2 – 4 weeks |
| Mole Salamander | Ambystoma talpoideum | 20 – 60 days |
| Northwestern salamander | Ambystoma gracile | 2 – 4 weeks days |
| Red salamander | Pseudotriton ruber | 2 – 3 months |
| Long-toed salamander | Ambystoma macrodactylum | 2 – 3 weeks |
| Two-lined salamander | Eurycea bislineata | 4 – 10 weeks |
| Jefferson salamander | Ambystoma jeffersonianum | 2 – 14 weeks |
| Red-backed salamander | Plethodon cinereus | 2 – 3 months |
| California Slender Salamander | Batrachoseps attenuatus | 2 -3 months |
| Arboreal salamander | Aneides lugubris | 3 – 4 months |
| Northern Slimy salamander | Plethodon glutinosus | 2 – 3 months |
| Mud salamander | Pseudotriton montanus | 3 – 4 months |
| Northern Dusky salamander | Desmognathus fuscus | 40 – 80 days |
| Four-toed salamander | Hemidactylium scutatum | 38 – 62 days |
| Long-tailed salamander | Eurycea longicauda | 4 – 12 weeks |
| Green salamander | Aneides aeneus | 80 – 90 days |
| Cave salamander | Eurycea lucifuga | 10 – 20 days |
| Small-mouthed salamander | Ambystoma texanum | 3 – 8 weeks |
Temperature Affects How Long Hatching Takes
Many salamander species have extended breeding seasons, and their eggs are exposed to a wide range of temperatures depending on the time of year when they are laid.
Salamander eggs laid when the weather is colder, usually take longer to hatch than those laid when the weather is warmer. This is because temperature affects embryonic development rates.
In general, most amphibian eggs will develop and hatch faster in warmer temperatures and slower in colder temperatures.
For this reason, many salamanders prefer to lay their eggs in open areas that get a lot of sunlight, as the water will be warmed by the sun, helping the embryos develop faster. Cold, shaded ponds with little sunlight will be avoided by many species.
In addition, amphibian eggs often have higher concentrations of melanin in their dorsal hemisphere which serves as protection from ultraviolet radiation, preventing it from penetrating into deeper layers of the egg.
It may also serve as a means of absorbing and retaining heat.
Other Factors That Affect Embryonic Development Rates
Apart from temperature, there are a few other factors that can influence how long the eggs of a particular salamander take to hatch.
1. Species
There are over 700 salamander species around the world. The embryos of some salamander species are genetically programmed to develop faster than others, provided that the environmental conditions are supportive.
For example, the eggs of salamanders which lay eggs in temporal pools that dry up in the summer, will usually hatch faster. This allows the larvae to develop and escape their ponds before the water dries out.
2. Water Depth
Eggs laid in shallow water typically hatch faster than those laid in deeper water. This is because shallow water tends to be warmer than deeper water.
Shallow receives more solar radiation and heat from the atmosphere, so it warms up faster than deeper water.
Shallower, smaller ponds also change temperature more quickly than larger, deeper ponds simply because less water has to be heated, or cooled.
Even in deeper water bodies, the top of the water is usually warmer than the bottom layers – and since warm water is less dense than colder water, it stays on top.
3. Water pH Level
Amphibian eggs are sensitive to acidity.
If the water is too acidic or basic, it can kill the embryos by preventing the expansion of perivitelline membranes and inhibiting hatching enzymes.
It can also delay hatching and disrupt embryonic development.
Some Salamanders Give Birth to Live Young
A few salamander species, most notably the fire salamander (Salamandra salamandra)and alpine salamander(Salamandra atra) do not lay eggs as most salamanders do. Rather, they give birth to live young.
These salamanders mate on land and fertilize their eggs internally, just like the fully terrestrial egg-laying salamanders. The embryos then develop inside their eggs’ inside the mother salamander’s body and hatch just before birth. This is known as “ovoviviparity“.
To give birth, a female fire salamander will crawl backward and immerse her cloaca in shallow, usually slow-moving water. She then releases about 15 to 70 well-developed aquatic larvae, but this number can vary depending on the subspecies.
However, alpine salamanders and Salamandra s. bernardez (a subspecies of fire salamander) are unique because they give birth to fully-developed juveniles who live a fully terrestrial life from the moment of their birth.
In these salamanders, an embryo develops from the first egg in each uterus. The embryo then feeds on the yolk of the other eggs which provide enough nutrition to sustain the developing embryo until it is ready to be born.
Pregnancy can last 2-3 years and the female salamander will give birth in a damp protected environment to keep the newborns safe from predators.
Common Questions
How many eggs do salamanders lay at a time?
Salamanders lay anywhere from 6 to as many as 500 eggs in a single breeding season, depending on the species. Salamanders that lay eggs on land tend to lay fewer eggs than those that lay eggs in the water, but this is not always the case.
Conclusion
The vast majority of salamanders reproduce by laying eggs, usually in the water. These eggs are typically attached to submerged rocks, twigs, and other vegetation, and will hatch in two to six weeks.
However, there are many factors that influence how long salamander eggs take to harsh, most notably the species, and temperature of the water.
In general, most amphibian eggs will develop and hatch faster in warmer temperatures and slower in colder temperatures.
Sources:
Lawrence E. Licht, Shedding Light on Ultraviolet Radiation and Amphibian Embryos, BioScience, Volume 53, Issue 6, June 2003, Pages 551–561, https://doi.org/10.1641/0006-3568(2003)053[0551:SLOURA]2.0.CO;2