I know what you’re thinking: how could you possibly select just a few favorite frogs? Aren’t they all special and glorious in their own way? And of course, I don’t deny that. This is just a highlight reel of a few particular frog species that I hold near and dear to my heart.
1. Gastric brooding frog
Full disclosure: they are extinct. I promise, the rest are still alive, and you can find them if you’re determined enough, but this one’s going to need some Jurassic Park treatment. If anyone deserves to be brought back, this frog does. The gastric brooding frog, belonging to the genus Rheobatrachus, was a native of Australia. After laying eggs and having them fertilized, female gastric-brooding frogs would swallow their eggs. The eggs would hatch in their mother’s stomach, and the tadpoles would develop into frogs, in the span of six to seven weeks. During this time, the mother frog stopped producing stomach acid and could not eat. Her stomach functioned as a uterus. When her babies had finished developing into small frogs, the mother frog would vomit out her children in a beautiful circle-of-life moment. What I would give to see this happen.
The exact reasons for the gastric brooding frog’s extinction are unclear, but pollution and habitat degradation certainly played a role. I personally think that letting something this amazing die out is one of humanity’s worst crimes. All too often, we don’t appreciate the insane things nature is just coming up with for free. There has been some discussion in the scientific community about “de-extinction” of the species, but this still remains largely theoretical.
(An honorable mention to Darwin’s frog, Rhinoderma darwinii, a still-living frog species in Chile and Argentina. Male Darwin’s frogs swallow their mate’s eggs and hold them in their vocal sac, where they hatch and develop from tadpoles to frogs. This is pretty cool too, but women just do things better. I don’t make the rules.)
2. Titicaca water frog
Lake Titicaca is a real lake. Don’t ask me whose idea the name was. The frog that lives there is called the Titicaca water frog (Telmatobius culeus), and that’s if you’re being nice — there’s a considerably more NSFW nickname, arising from the frog’s baggy, wrinkled folds of skin. This extra skin provides extra surface area, so the frogs can absorb more oxygen in their high-altitude environment. Titicaca water frogs are entirely aquatic. They’re some of the largest frogs to live the all-underwater lifestyle, with bodies that are 4 to 8 inches long (and outstretched legs twice that length). Their use in traditional medicine, as well as pollution to their environment, has put them on the depressingly inclusive club of endangered species.
3. Paradoxical frog
Buckle up. This sounds so fake but it’s not. Also known as the shrinking frog, Pseudis paradoxa takes the message of Taylor Swift’s “Never Grow Up” to the next level. Not to say they don’t get older — they turn from tadpoles to frogs — but they definitely don’t *grow* up. As tadpoles, these frogs are up to 11 inches long. As adults, their bodies are a humble 1.5 to 3 inches long. They literally shrink. Don’t believe me? I wouldn’t believe me. I read about this in a science book and thought it was a prank by the editor. It was not. These freaks actually exist. They live in South America, primarily in the Amazon.
4. Glass frog
If these guys ever start caring about the field of medicine, it’s over for us humans. When it comes to viewing their own kind’s anatomy, glass frogs (family Centrolenidae) have a massive leg up, and not just because frogs have massive legs compared to their bodies. Glass frogs have see-through skin on their bellies. The skin becomes more transparent when the frogs are at rest, because they tuck away most of their red blood cells in their liver while they sleep. Their organs are bared for the whole world (or at least the forests of Central and South America) to see. They have no secrets, really. Hearts out in the open. Can you imagine how easy it would be to learn the intricacies of anatomy when you can see what most of everyone’s anatomy looks like?
I know it might seem like a bit of a stretch to imagine them becoming anatomists and surgeons, but consider this: one glass frog species has already adopted the human phenomenon of DILFism. According to a National Geographic article I frequently think about, male glass frogs who haven’t mated yet will stand next to abandoned clutches of eggs, pretending to guard them. This attracts females, who think he’s an experienced and attentive father. A bit of lying is forgivable when there’s not much you can hide. And to be fair, a common trait among many glass frog species is that males are responsible for guarding their eggs — responsible fatherhood is the norm.
Also, one particular glass frog species from Costa Rica — Hyalinobatrachium dianae — looks uncannily like Kermit the frog. Like, it’s a bit scary. Makes you wonder what the original Kermit would look like if you could see his insides. I’m telling you, these guys are coming for us.
5. Wood frog
If I may assign this frog a Noah Kahan song, it’s “Northern Attitude” for sure. Wood frogs (Lithobates sylvaticus) live farther north than any other frog species on the planet. They range from the Northeast and Great Lakes regions of the U.S. (so, yes, you can find them here in Connecticut) all the way to Alaska and northern Canada, even north of the Arctic Circle. How do they do it? They freeze solid. Completely solid. If you need someone to do you a solid, ask a wood frog. When winter falls, ice crystals form between the frog’s cells, their livers pump glucose into the cells to stop internal structures from freezing, and the frogs don’t eat or breathe for months. They don’t even have a heartbeat. But in the spring, they thaw out good as new and hop off to find a vernal pool for breeding.
6. Golden poison frog
I could have included all poison dart frogs here in general, because they’re all beautiful and amazing. But I decided to go specifically with the golden poison frog (Phyllobates terribilis) because it’s the boss level of the poison dart frogs. The average golden poison frog is 1-2 inches in length and contains about one milligram of poison. This is enough to kill 10 to 20 people. The poison, batrachotoxin, stops nerves from transmitting impulses, so things shut down pretty quickly. If you eat this frog, or if you don’t wash your hands after touching one and then go out for a nice dinner, you’ve got ten minutes max. No cure exists. Golden poison frogs are hard to find, living only in a small area of rainforest in Colombia, so this probably won’t happen to you. Just food for thought.
Fun fact: poison dart frogs are so titled because indigenous people have historically used the frogs’ poison on the tips of arrows, making them immensely more deadly. In the case of a golden poison frog, the arrow can remain poisonous for over a year. Again, you probably don’t have to worry about this, but some food for thought.
7. Mini mum
Okay, I’ll admit, this frog is a bit of a nepo baby. Not for who its parents are, but because the attention it gets comes pretty much entirely from its name. The frog doesn’t even have a common name; it’s just the Latin name, Mini mum. The two other members of the genus, Mini ature and Mini scule, are in similar positions. Nothing is morphologically special about these Madagascan frogs, except that they’re tiny. Really tiny. Like, we’re talking 0.3 to 0.4 inches long, or 8 to 11 millimeters. These Mini frogs aren’t technically the smallest frogs in the world (that honor goes to Paedophryne amauensis of Papua New Guinea), but they aren’t far off. They can fit quite comfortably on a human fingernail.
So yeah! These are my favorite frogs. I wish them nothing but the best. Granted, amphibians are dying en masse from chytrid fungus and habitat loss, and they’re extremely sensitive to pollution on account of the skin-breathing thing, so we all need to do a lot better for them. If learning about these species doesn’t inspire people, I don’t know what will. Earth is crazy.