It is well-known that frogs generally inhabit freshwater spaces, such as ponds, marshes, and inland water bodies.
My grandmother had frogs on her property and, to my dismay, would use salt to deter them from coming back.
Using salt has become a popular method for deterring frogs. However, many amphibian lovers wonder if salt could kill these innocent creatures.
Frogs can die due to salt exposure, depending on the species and the method of contact. Salt causes dehydration and disrupts their body functions, which can cause illness or death. Salt can be used in moderation to repel frogs around the home, but should never be put directly onto a frog.
While mild salt usage is more likely to cause discomfort and skin irritation, excessive salt exposure can cause irreversible damage to frogs.
Join us me as I discuss how salt exposure affects frogs and why some frogs are more tolerant than others.
See how to safely use salt to keep frogs away, without killing them on our blog
Salt Causes Dehydration in Frogs
Minor exposure to salt can generally cause skin irritation and discomfort in frogs, which is the primary reason why salt is used as a deterrent. However, salt is not safe for frogs overall, and excessive exposure can lead to a wide range of negative outcomes including death.
Frogs need moisture to survive, whether they are terrestrial, arboreal, or aquatic. Some frog species may be far more tolerant of drier conditions than others.
However, they still need to maintain an adequate level of water content in their bodies to achieve optimal functionality.
It is fairly well-known that salt causes dehydration in the skin, regardless of the type of animal. Typically, the level of dehydration will depend on the quantity of salt, which is the primary influence on how dehydrated frogs may become due to salt exposure.
Coming into contact with salt due to hopping on salt-sprinkled surfaces will likely only cause minor dehydration in the area of contact, meaning that the chances of recovery are fairly high.
But, frogs can die from dehydration with excessive salt exposure, such as throwing salt onto them (which is cruel and inhumane, do not do this to frogs).
Salt Can Disrupt a Frog’s Bodily Functions
Most frog species are efficient at water regulation through their skin and retain salt through the transport of sodium and chlorine ions. This means that most species are vulnerable to excessive salt, and higher tolerance levels will likely involve adaptations in the physiological transfer of ions through the skin.
While dehydration is the primary concern of salt exposure, the sensitive and permeable nature of frogs’ skin is a massive consideration.
Salt disrupts the water and ionic exchange across permeable membranes, which can be incredibly dangerous for frogs.
Salt exposure will likely cause disruptions in osmosis into frog skin and the blood’s circulation processes.
Salt Can Cause Deformations in Frogs
Salt exposure can affect frogs at any stage of metamorphic development, but they are most vulnerable to the negative consequences of salt during the embryo and larval stages. Frogs are incredibly sensitive, but they are far more prone to injury, deformation, and harm during early development.
A few studies into the potential salt resistance in certain frog species discovered negative and long-term effects when frogs were exposed to excessive salt during the embryo or larval phases.
While many can survive, frog larvae raised in saline environments can suffer abnormalities.
Just about every frog species naturally prefers freshwater since these habitats are generally free from salt-related risks.
As a result, most frog species are generally absent in saline environments on a broad scale.
Some Frogs Have Adapted to Survive Saltwater
In 2015, scientists Hopkins and Brodie identified 124 frog species able to inhabit saltwater habitats. This number represents only 1.6% of over 7,400 known frog species, and more research is needed to understand how frogs are evolving to live in brackish conditions.
Although freshwater frogs are by far more dominant and functional, it has been found that there are a few species that have managed to adapt to saltwater over time.
But, this tolerance depends on the environmental conditions within their natural habitats. These tolerance levels are especially observable in many frog species that live within coastal regions and marshes.
In 1872, Charles Darwin found that only one Indian frog species could tolerate saltwater, but various additional studies have been conducted since then.
To date, 144 amphibian species stemming from 28 amphibian families have shown varying tolerance levels concerning saltwater.
This number includes 124 frog species, in addition to certain salamanders, toads, and caecilians.
Most cases where salt tolerance was observed described coastal regions and areas that experience ocean floods, which send waves of seawater into otherwise freshwater habitats.
Some frog species that can withstand moderate saltwater conditions include:
|Frog Species||Scientific Name|
|Columbia Spotted Frog||Rana luteiventris|
|Lowland Leopard Frog||Lithobates yavapaiensis|
|Southern Leopard Frog||Lithobates sphenocephalus|
|Pacific Tree Frog||Pseudacris regilla|
|Tiger Frog||Rana pipiens|
|Clawed Frog||Xenopus laevis|
|Mediterranean Painted Frog||Discoglossus pictus|
|Tyrrhenian Painted Frog||Discoglossus sardus|
|American Bullfrog||Lithobates catesbeianus|
|Spring Peeper||Pseudacris crucifer|
Many cases of frog species that can tolerate saltwater have observed physiological adaptations and genetic variables.
Although, there are still many underlying questions that will take time and research to find reasonable answers.
Below are examples of iconic frog species that have adapted to natural salt levels.
Crab-Eating Frogs Are Salt-Tolerant Frogs
Crab-Eating Frogs (Fejervarya cancrivora) can thrive in freshwater in addition to 75% seawater, and they can adapt from one water type to the other within only a matter of hours. They have this ability since they can rapidly alter the shifting levels of their body tissue’s urea, allowing them to evade excessive water loss.
This incredible frog species lives in Southeast Asian mangrove swamps, which experience daily floods due to tidal fluctuations.
These conditions result in predictable saltwater levels in the surrounding standing water bodies.
They also have three glands within their skin, namely mucous glands, mixed glands, and vacuolated glands.
These glands help buffer the excessive salt, which would otherwise enter the body through the skin and cause varying levels of dehydration or disruption in skin functionality.
While most frogs cannot withstand saltwater to any degree, a few frog species have somehow altered their physiology for their species’ survival and continuation.
Still, these cases are generally naturally occurring, and frogs should always be sheltered from excessive salt or saltwater to ensure their wellbeing.
More About Frogs And Salt
Further research is needed to understand how frogs are adapting to salt, saltwater, and brackish conditions based on the species, environment, life cycle stage, and methods (genetic, cutaneous, etc) used to adapt to their evolving habitats.
Learn more about frogs in these guides on our blog: