The Most Fantastic (Real) Animals You Never Heard Of

Pyrosome

Almost exactly 7 years ago, in April 2010, I told you about animals about which I was certain you had never heard: the Rhinogrades [see "The Most Fantastic Animals You Never Heard Of"]. However, since that was posted on April 1st -- aka April Fools' Day -- you might not trust anything I have to tell you during April about creatures that do not seem to be real. But now I am going to tell you now about creatures that do not seem to be real. But they are.

Pyrosome

As you are scuba diving, you come across an immortal creature that looks like a giant sea worm with a gaping mouth that can swallow you whole. As you scream into your mask, the monster even begins to glow. You must be a goner! Well, you are not -- unless, of course, you have a heart condition, which begs the question why you are scuba diving in the first place.

Pyrosomes, also known as Fire Salps, are not sea worms. You probably don't know what a "salp" is, and it probably would not be any more enlightening if I clarified that they are planktonic tunicates. However, I can assure you that they are not dangerous. A Pyrosome is not even a single animal, but rather a colony of hundreds or thousands of a tiny animal called a zooid -- yeah, that doesn't sound extraterrestrial at all. Each zooid is only a few millimeters long, but they connect to each other through a common gelatinous layer, forming a long hollow tube-like structure that can be longer than a whale. The zooids themselves are like tubes as well: Facing outwards from the Pyrosome structure, they suck in water; and then expel the water, minus all the nutrients from microscopic plant cells, into the interior of the Pyrosome. 

The Pyrosome moves through the water primarily through the natural action of ocean currents, but it also has minimal capabilities to move in a certain direction when all the zooids move their cilia in coordination, or when they coordinate their sucking/expelling actions, creating a jet propulsion action -- if a jet were to move a few meters an hour.

But, wait, there's more! Pyrosomes are also bioluminescent. They flash a blue-green light, or sometimes an orange one. This is believed to be a form of protection, since what predator really wants something in its stomach that is glowing?

And didn't I mention something about "immortal." Well, zooids reproduce through the process of budding, similar to the Hydras we studied in high school. Since every zooid in each Pyrosome has the same DNA structure, and is completely identical to the one that started it all, through a type of cloning process, it could be said that that zooid will live on as long as it continues to create new buds from itself. This process also allows a Pyrosome to expand in size or shrink, based on the environment -- availability of food, injuries, predators, etc.

So the next time you see a whale-sized glowing worm heading your way, you might not have to flee, but I leave it up to you whether you pet it.

Slime Mold

Slime Mold "Slug"

You have heard of a single-celled creature that can grow from microscopic size to the point that it can completely engulf a human. It can move, and even though it has no brain or eyes, it can communicate, learn, and even teach. Yes, you know it as "The Blob," from the 1958 film of that name. Well, run for the hills, because there is a creature like this already here on Earth! Actually, you don't have to run; you can probably saunter or leisurely stroll, and you'll still easily escape.

You might also have heard of Slime Mold; perhaps someone even has called you one. However, you probably have never seen one or can describe one, besides muttering, "It's a mold that is slimy." Well, no, it's not. A Slime Mold is not a mold, and it's open to interpretation whether it qualifies as slimy. Slime Molds are not classified as fungi or plants. But neither are they considered animals. Huh? So what does that leave? They are protists. A protist is an organism that cannot be biologically grouped with any of the three mentioned above.

There are over 900 species of Slime Mold, in a vast array of colors, but they basically are one-celled organisms, like an Amoeba. Unlike amoebas, many Slime Molds are visible to the naked eye and can even reach lengths of 4 meters. Millions of these single cells often combine with each other, growing at an incredible pace -- even though it remains as a single cell, it will include the nuclei of the all the cells that merged. 

Slime Molds have forced scientists to reevaluate the definitions of such terms such as intelligence, habituation (non-response to insignificant stimuli), altruism (sacrifice of oneself for the good of others), learning, and teaching. Even though it has no brain, eyes, mouth, or appendages of any kind, these Slime Molds will form into a slug-like entity that not only moves across the ground searching for food, but can learn to solve a maze, and even pass on such information to other cells it combines with. It will create "buds" that will send reproductive spores into the air, sacrificing itself in the effort. 

All we can hope for now is that they don't watch the 1988 remake of "The Blob" and get some new ideas, and a better script. 

Slime Mold

 Cave Angel Fish

You've all heard the evolutionary tale about how life on Earth began in the oceans, and how some revolutionary fish first dipped its toes (fins) onto solid land. And from there the fins evolved into legs, and then there were dinosaurs, and then humans. Well, perhaps not in such a straight line, but you get my point. You probably also have heard about lungfish and mudskippers, which are present-day fish that can "walk" across solid land or slither across mud using modified fins. They can either breathe the air through modified gills, or bring a supply of air with them. Some of these species actually live on land more than they do in water. 

Cave Angel Fish

Ok, so that's cool. But what about a fish that can also climb walls? Apparently there's only one that can do this, the Cave Angel Fish (Cryptotora thamicola), which is only found in a connected system ofcaves in Thailand. As most cavefish, it has no eyes and very little color. Unlike the other "walking" fish mentioned above, the CAF uses its fins to climb up waterfalls, clinging to the rockface like a salamander and using a tetrapod-like diagonal-couplets lateral sequence gait. That's just a very convoluted way of saying that it walks like a four-legged animal rather than slithering, skipping, or rolling on land like other fish do. So, the next time your neighbors explain that they are building a wall to keep out undesirables, ask them how they plan to stop the fish.

Pink Frogmouth 

Speaking of walking fish, have you ever heard of a fish that walks more than it swims, but never ventures out of the water onto land? The Pink Frogmouth (Chaunax pictus) does that. It uses its fins to walk along the ocean bottom. It has the ability to swim, but it does so rather clumsily.

Pink Frogmouth

Sea Slugs

Eastern Emerald Elysia

Just the concept of an ocean-going slug is a bit gross. Just think of a snail without a shell, which we know as a slug -- but it lives completely under water. There are thousands of different species of Sea Slugs, so I will not review each one. However, I do want to point out a few that have some unique characteristics.

Eastern Emerald Elysia

How about an animal that uses photosynthesis to obtain its energy? Yes, I said "animal," not "plant." Chlorophyll converts sunlight into energy through the process of photosynthesis. The chlorophyll in plants is located in special cell sub-units called chloroplasts. The Eastern Emerald Elysia (Elysia chlorotica) is a sea slug. It specializes in ingesting algae. However, although it ingests the algae, it doesn't completely digest it. The EEE does not excrete the algae's chloroplasts, instead retaining them within its own body for up to two weeks, utilizing the cells' abilities to create energy. This process of "stealing" one's prized plasts is called kleptoplasty. The slug is primarily translucent, so the millions of internal chloroplasts give it a green color. Oh, and did I mention that the EEE is in the shape of a leaf? How convenient. Cavaet emptor: If you are a vegetarian and a restaurant offers you a delicious-sounding Emerald Elysia salad, you might want to pass on that. Actually, even if you're not a vegetarian, I suggest the Cobb salad.

Nudibranches

A Nudibranch is a subset of sea slugs. The Hooded Nudibranch (Melibe leonina) looks like a floating piece of kelp -- except for its ghastly mouth (it's "hood"), which widens larger than its own body to capture prey. 

Hooded Nudibranch

Similarly, the nudibranch Melibe viridis feeds in a similar way, but often on the ocean floor -- and it moves around on pseudo-appendages that resemble the legs of some weird insect or anthropod. Just picture a slug walking around on legs. Eww.

Melibe viridis