Alien Globs are Coming to a Forest Near You! - Sorta...

2/27/2024

The "Mystery Glob" | © Ty Smith

Social Media Reports

If you are on social media, you may have seen someone post a gelatinous mass (like the one above) in a puddle, or maybe you have seen this yourself. Sometimes they are white, red, green, or even clear with materials that "look like seeds or worms inside". They can range in size anywhere from golf ball-sized to larger than a softball, but are usually fist-sized. Witnesses observe these "mystery globs" in small puddles or wet places on the forest floor. I have seen the "super-sleuths" on Facebook suggest these are everything from a fungus, to tree sap, to "alien snot" (hopefully jokingly but some people do believe the earth is flat). Others suggest fish or frog eggs, which is much closer to the truth.

Massive "Glob" | © Ty Smith

Do not fear, these "globs" are not a crazy fungus or alien in nature. They are simply Spotted Salamander (Ambystoma maculatum) egg masses. Why are they so weird looking? Why are they four different colors? How can you tell them from frog eggs? I am glad you asked, because it is all far cooler than aliens.

Tonight We March!

Adult Spotted Salamander A.K.A. "The Mothership" | © Ty Smith

Spotted Salamanders are a very abundant Ambystoma species in most of Virginia and the eastern US all together. That said, they are rarely seen for how common they are, because they are fossorial (living underground). There they feed on soft-bodied invertebrates like worms, crickets, and grubs. That said, they do move closer to the surface in winter. Why would a cold-blooded animal get closer to the cold? Because these amphibians, like several others, are very cold hardy. Many amphibians have high levels of glucose in their blood, which acts as an "antifreeze". Their metabolism can handle the temperature drops as well.

Amphibians handle being ectothermic (cold-blooded) very different to reptiles. Reptiles have moisture retaining skin and scales, and therefore can bask in the sun to get what they need. Amphibians would lose all moisture and very quickly and die if they did this. Does this make amphibians weird? No, because reptiles are really the weird ones... Reptiles are ectotherms, but very "modern" ectotherms. Fish would have never survived if they couldn't operate in somewhat cool temperatures. Imagine fish coming out of the water to bask in the sun. This thought is just so funny to me and it brings me so much joy to just imagine. Anyway, fish can't afford to completely shut-down in the winter, because of predators and changes to the water (freezing, water levels dropping, oxygen turnovers, etc.). Their response is to slow their metabolism way down, but not "shut it off", like animals that hibernate. Naturally amphibians would retain some cold-hardiness. Reptiles are amniotes, which have revolutionized ectothermy to the point that many evolved endothermy and reptiles are stuck in that weird "in between" stage where they are still ectotherms, but they have high metabolisms and rely on heat to regulate that metabolism.

Let's get back to our salamanders. Usually January-March (in Virginia at least), weather dependent, we see Spotted Salamanders arise with the seasonal rain and migrate to vernal pools. This can happen a few ways, but typically males are the first to arrive in the pools. Early females may hang out in the pools for a few days, getting their oxygen from gulping air, processing it with their "primitive" lungs, and absorbing oxygen straight through their skin. Males then leave packets of... well we will say "genetic material" for the families, called spermatophores. These look like tiny pieces of popcorn (yummy), and are left on sticks and leaves in the vernal pools.

Spermatophores deposited on leaves in a vernal pool | © Ty Smith

Oh, and incase you didn't know, vernal pools, or ephemeral pools, are pools of water that are filled by seasonal rains. In virginia, they typically are here in our "wet season", and we see them filled in December through June. The females then arrive to the pools and pick-up these spermatophores with their cloaca (the one vent that contains all of the reproductive organs and the "end" for the digestive tract). She will then hide in the pool and allow some time for her eggs to fertilize internally.

Dozens of Spotted Salamander egg masses laid along one branch in a vernal pool | © Ty Smith

Keep in mind now that a female Spotted Salamander is about the size of a hot dog, and she can lay an egg mass larger than a softball. Now, how does a female lay an egg mass that is much larger than she is? Good question. She doesn't. The eggs are coated in a layer of proteins that absorb water and swell (similar to the "water crystals" people use for plants). Often times, females will lay their eggs in groups, on a single object like a stick or leaf or even on another egg mass. Sometimes we see two or more egg masses together to make the appearance of a giant mass. Sometimes they seem close to basketball-sized. The masses on the left took up an area of about 7 square feet!

Egg Color

Why are there so many different colors of egg masses? Well, female Spotted Salamanders lay three "morphs" of egg masses, seen below.

Clear egg mass | © Ty Smith

Semi-opaque egg mass | © Ty Smith

Opaque egg mass | © Ty Smith

These are considered "morphs" because each color is controlled by a single gene and not the choice of the female persay. What is the benefit to laying different colored eggs? Well, it is not so much that they are different colors, it is how much light they let in. So, why is lighting an issue for eggs? Well, it is mainly an issue if you are growing plants in and on the eggs.

Yup, do you see this green egg mass to the right? It is full of Oophila amblystomatis, a green algae (single-celled plant) that grows in and on the eggs as well as the cells of the embryos. You may think, "This is gross! Why would you grow algae?" Well, these eggs are sheltered in a deep layer of slime in a stagnant body of water, so oxygen is pretty low. It is nice to have your own plants growing in and on you to produce oxygen if you are in such conditions. Also, it is nice when you can synthesize energy and nutrients from the algae, making you effectively photosynthetic yourself. That is what they do! Spotted Salamanders were the first vertebrate that we found to be photosynthetic.

Oophila amblystomatis visible in egg mass | © Ty Smith

Egg mass with red Oophila amblystomatis visible on the outside and green on the inside | © Ty Smith

Spotted Salamanders aren't the only amphibians that have an algae that does this, as Wood Frog eggs also host this or a similar algae species. That said, plants need pretty specific light requirements though, and while the algae can turn red when it is getting too much light, leaving a low-light plant in the bright sun can kill the plant. So, if you block sunlight with an opaque membrane, you can keep this from happening. If you don't have a lot of sunlight, clear masses will let more light in for the algae. Pretty much, the salamander does not know if the pool gets a lot of sun or not, so it is a genetic "shot in the dark" and whichever eggs provide the algae with a place to thrive, are the ones that survive. Over time we do see salamanders favor one egg type in a pool, but with us clearing and replanting forest, these variable types have been somewhat selected for in the last few hundred years.

Spotted Salamander Eggs vs Frog Eggs

So, in simple, the frogs that breed at this time do not lay egg masses encased with this thick gel membrane of this size. Here are some common winter amphibian egg masses and similar organisms to compare.

Southern Leopard Frog egg mass. Note: it is similar to the Wood Frog mass, but each egg has less of a membrane around the embryo, making each egg about the size of a pea. | © Ty Smith

Upland Chorus Frog egg mass. Note: The eggs are suspended in a gel casing like the Spotted Salamander, but the mass is about the size of a quarter and the individual egg membranes are not visible. | © Ty Smith

Magnificent Bryozoan. This is an awesome colony of protist, but they are found in lakes, have a "scaly" appearance, and do not have individual eggs inside because they are not an egg mass... | © Ty Smith

Back to the Posts

So, if these eggs are typically laid in vernal pools, why are they just randomly in the forest or in puddles? Well, a vernal pool is pretty much a specialized puddle. It is easy for salamanders to confuse a small puddle in the trail for a pool, and lay eggs. These puddles can then dry up. Also, curious animals and children could move these masses from the pools to dry land to investigate them. They do dry out as well, giving some of them a "leathery" appearance, and if they are not returned to the water they will dry out completely and die. So, should you move them too a pool if you find them randomly? Yes, you would save the eggs, but is it worth it?

Sometimes nature should be left to take its course. If you think it was removed by a human, that is one thing, but if the female miscalculated and left them there, maybe those genes are not good to pass on. Also, if they have been exposed to air, they could have picked-up an infection that you could be bringing back to the pool. You could be throwing dead eggs back into the pool, which could cause the growth of some pathogens. I say this not to discourage you, but to say that I don't know what the best solution is. Think it through, and make a decision based on the situation.

So, I hope you have learned something about Spotted Salamander breeding. There is not many eggs that could prompt such an article, and that should show how crazy this species truly is! We think of amphibian eggs as being straightforward, but bare in mind amphibians did not stop evolving when they arose. These animals are to this day evolving, and adapting to survive in our ever changing world. These eggs show us too that evolution can do more than change a body plan, but every part of the growing process. Salamanders are a very important part of our ecosystem, and maybe one day I will dig into a deep article on that, but for now just know you can tell all of your friends what this "alien glob" is when they see it in the forest.