For this post I went back in time to the years of my Bachelors in Animal Biology, took a lil’ stroll in the old mind palace if you will, to when I learned about so many cool animals I never even knew existed. Here I compiled a random sampling of my favourites with some recent research that’s been done on each species. I actually learned a lot researching for this article, there’s much more going on in the microcosms of these species’ lives than I expected. Enjoy a peek into the secret worlds of these fascinating creatures!
1. The Common Seadragon: Phyllopteryx taeniolatus
Seadragons are basically the majestic, tricked-out, LSD version of seahorses. This species is also called the weedy seadragon because its lobe-like fins and squiggly shape help it fit in quite well with seaweed for camouflage. Being closely related to seahorses, they also have that fun feminist slant where the male incubates and cares for the eggs. Male seadragons actually lack a pouch to store the eggs, opting instead to carry eggs on their tail. But mostly, they are just entrancingly gorgeous to flick through on Google images for a good half-hour. Individual seadragons can actually be identified uniquely from one another using the pattern of spots and blotches on their abdomens! It’s like a fingerprint, except huge and all over your stomach. Like maybe if I wanted to dress up as a seadragon for Halloween, I could just paint “MY NAME IS SARAH” on my stomach. A totally accessible joke that everyone will understand.
It was actually only just quite recently that we studied the movement patterns of seadragons, despite them being recognized as Near Threatened by the IUCN (the international organization that classifies endangered species) and targeted by the international aquarium trade. And we found that…they do not move. They basically stay in the same area throughout the year, and the only time they migrate anywhere is when pregnant males move to shallower water to give birth (aww). It seems like quite a peaceful, idyllic life as a seadragon, doesn’t it? Luckily they are not a significant target for the industry of traditional Chinese medicine, nor are they commonly caught as bycatch. The main threat facing the seadragon is loss of habitat (as it seems to me, is often the unfortunate case for many species). Captive breeding efforts and a spectacularly named citizen science initiative called Dragon Search, whereby divers are encouraged to report sightings, have been established to help this species.
Alright, that’s a gentle introduction, because it’s about to get weird.
2. The Velvet Worms: Onychophora
Isn’t it bizarre that there can be 200 species of something you never had a clue existed? Welcome to invertebrate biology. My second-year class “Survey of the Invertebrates” was definitely the class where I was introduced to the most animals I’d never heard of before. I am strangely fond of the velvet worms. I mean, they’re trying their very hardest to show you that invertebrates can be cute too.
There is so much weird shit I could tell you about velvet worms without even going to the trouble of digging for recent research articles on them: their feet are called “lobopods.” They can bear live young. They have slime glands within modified feet ON THE SIDE OF THEIR HEADS that they use to projectile-slime and ensnare their prey. They have complex brains that enable them to live in groups with social hierarchies established through dominance. There exists a species of velvet worm that no one has ever observed a male of: females reproduce asexually through a process called parthenogenesis. I’m seriously not bull-shitting you with any of this.
Perhaps the most fascinating yarn I can spin you about onychophorans is the bizarre mating behaviour observed in some species of the Peripatopsidae, a taxon found in South Africa, Australasia and Chile. I have two words for you: dermal insemination. Unfortunately this means exactly what you think it means: males transfer a spermatophore (a package of several sperm heads) directly onto the skin of the female. From there, the spermatophore fuses with the skin of the female and the sperm are deposited directly into the body cavity of the female. They migrate freely inside the female and somehow find their way to the ovaries! It has been reported that females can viably store sperm inside their bodies for their entire lifetime and thus might be able to control when their eggs become fertilized. Now that’s a feminist species.
Curiously, velvet worms come in all kinds of beautiful colours and patterns as well:
All in all, a totally under-appreciated and spectacular group of creatures! Now you know.
3. The Water Bear/Moss Piglet: Tardigrada
Tardigrades have gained some fame on the internet because they truly are outrageous: able to withstand temperatures from -272°C (-458°F; 1 Kelvin – almost absolute zero) to 150°C (300° F; 420 K), the vacuum of outer space, radiation exposure at doses hundreds of times the lethal dose for humans, and even able to survive without food or water for longer than 30 years, it makes you doubt whether an apocalypse could ever truly wipe out life on Earth. Surely if nothing else, the tardigrades will inherit this planet.
It’s actually a very exciting time to think about tardigrades because just last week a research group published their solution to the mystery of HOW tardigrades can survive such extreme conditions as complete dehydration; it’s a well-known fact tardigrades seem able to survive just about anything, but we didn’t have a clue as to how until this research came out. Incredibly, tardigrades produce unique proteins that form a glass structure when the tardigrade dries out, essentially freezing the other molecules of the tardigrade’s body in place and preventing them from being damaged. Basically, tardigrades protect themselves by turning into glass! These tardigrade-specific intrinsically disordered proteins (TDPs) represent more than just a “fun fact” kind of discovery: researchers are hoping that we can harness the power of these molecules to help transport vaccines and pharmaceuticals at room temperature. That would allow us to deliver these types of medicines more readily to remote and developing areas of the world, as the cost and logistics of refrigerating supplies is currently a big hurdle. Thanks, moss piglets!
4. The Saiga Antelope: Saiga tatarica
Why does it have a trunk?! That doesn’t even look right. The Saiga antelope looks a bit like a creature out of the ice age, and that’s probably because it is: evidence of this species dates back to the late Pleistocene epoch ~0.1 million years ago. Today they are found only in Russia, Kazakhstan and Mongolia, but previously they were thought to range widely across Europe and northern Canada as well, back when we were all connected by the Beringian land bridge. In doing my research on the Saiga antelope I found that they’re actually in a bit of pickle. Well, a lot of a pickle. A lot of a salty, salty, well-brined cucumber.
First of all, Saiga antelope are classified as Critically Endangered by the IUCN, mainly because they are hunted for the Chinese traditional medicine trade for their horn. Then in May 2015, hundreds of thousands of Saiga antelope mysteriously died, an event that was incredibly captured on camera by the BBC when filming for Planet Earth II. This constituted a loss of half the world’s population of this species, the BBC tragically describing the scene as “littered with corpses.”
Since that mass mortality event, it has been determined that the deaths were caused by toxic infections of a normally harmless bacterium living in the nasal cavities of Saiga antelope: Pasturella multocida. Now, research is focussing on what caused a normal member of the antelopes’ microbiome to revolt so viciously: this bacterium is known to “run amok” occasionally in other species, but never causing nearly 100% mortality as it did in 2015 for the Saiga. So the story of the Saiga is a sad one for now, but a dedicated group of researchers, veterinarians and conservationists are working hard to make progress. For the meantime, let’s all consider how more animals should probably have trunks:
And if you’re feeling generous, you can always donate to the World Wildlife Fund to help with the recovery of this unique, delightful, and unfortunately troubled species here. (I mean, now that I’ve guilted you with a baby photo, it’s kinda hard not to click…sorry about that).
5. The Caecilians: Apoda
In the peaceful days of my youth, I used to think that amphibians were frogs, toads, and salamanders. This assumption was rudely interrupted when I was informed that caecilians exist. Aptly labeled as the “apodans” (meaning “no feet”), these limbless tubular buddies are blind and highly adapted for burrowing. They can be so tiny as to resemble earthworms and so large as to be snake-like. Like our other favourite unglamorous soft-bodied tube creature, the velvet worm, there exists nearly 200 species of caecilians. Nature once again proving that the gross things in life tend to be the most numerous, am I right? #relatable
Anyways, what’s really interesting about caecilians besides the fact that they exist (kinda blows me away on its own) is that their evolutionary history still remains quite a mystery. Despite having a solid internal skeleton and spending a lot of time in the mud, characteristics that usually make you well-represented in the fossil record, fossils of caecilians are rare. Scientists have gone to amazing lengths to glean as much as possible from what little they have: using a hyper high-resolution form of a CAT scan (called micro-computer tomography; this technology has been described as essentially “3D microscopy”), researchers were able to examine a Jurassic caecilian fossil in detail without having to destroy the valuable specimen.
It turned out that not only did this fossil represent the oldest ancestor of all caecilians, but it also likely represents what the common ancestor for all amphibians would have looked like. This is particularly exciting because it has been historically difficult to make sense of how amphibians evolved. Their evolutionary tree has been a bit of a mess to figure out, but studying ancient caecilians has helped us reconstruct the history of the whole amphibian lineage better! Who knew a slimy tubey guy who hides in the dirt all day could be so useful?
6. The Takahe: Porphyrio hochstetteri
No one could really blame you for not knowing the takahe exists, because for a long time we really did think they were non-existent. Not as in: mythical creatures that never existed in the first place, but as in: extinct. This species was thought to have been wiped out until a tiny surviving population was discovered in a remote region of the Murchison Mountains of New Zealand in 1948. Wiped out by what? Well, the usual: human interference. Takahe were, and still are, threatened by various invasive species brought to New Zealand by people. Introduced deer compete with the takahe for the same food, and introduced stoats (a weasel-like animal) prey on them. Historically humans also hunted the takahe intensively and wiped out much of their natural swampland habitat.
Nowadays the takahe are doing a bit better, having been re-established on five predator-free islands and protected by efforts to reduce the invasive deer population in the Murchison Mountains. Sadly, as of 2015 there were only approximately 230 individuals, so efforts are still going to strong to conserve and research this species! The silver lining to this unfortunate situation is that a lot of dollars go towards takahe work and research, allowing us to rapidly learn about how to conserve and protect these bizarre blue birds.
Since takahe are monitored quite closely we have a lot more information about each individual than we normally might, allowing for researchers to follow many individuals across their lifetimes. In 2010 a research group published a study about how inbreeding effects can actually accumulate in their intensity across the lifetime of individual takahe. In their small, fragmented populations, takahe are mating frequently with mates that are related. This damages their genetic diversity, and the negative impacts of this are borne out throughout the individual’s lifetime. For example, an individual might be less fertile as a result of inbreeding: this could make the individual less attractive to other mates, reducing mating success, but would also reduce the number of offspring the individual can produce when they do mate later in life. Previous studies had mainly measured such inbreeding effects only at a single life-stage for other species, potentially underestimating the cumulative effects across the animal’s entire life.
Ending on a bit of a sober note with the takahe, I know: but really, they are quite a success story, having come back from being assumed to be extinct! They really take on a mythical status for me, knowing that fact. I hope you enjoyed this dive into the biology of little-known but loved animals!
Note: I know, I know, even though I just recently disparaged listicles, here I am writing another one. Listicles can suck when they distill down big ideas too simplistically, exist solely as clickbait, or just reiterate the same idea multiple times but using different words (I think that’s my most hated type of listicle, I can actively feel my precious spare time being lain to waste like so many pillaged towns). But I also agree that the listicle has some redeeming qualities! So I hope you found this one good and worthy of your time.