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Paraloricaria (image from Paul Louis Oudart – Voyage dans l’Amérique méridionale)
Do you remember all of the catfish which used to be on Ferrebeekeeper? There were underground catfish, coral reef catfish, and giant catfish. We even featured Ancient Egyptian catfish and nightmare vampire catfish that crawl inside people! Sigh…happy times. That obsession with catfish was one of the factors which launched this blog. It is extraordinary how many different species of catfish there are and how wildly diverse this one order of lifeforms is. Catfish have extraordinary senses which humans lack entirely. They can be tender and solicitous parents and they are capable of building structures. Ranging in size from nearly microscopic to enormous, the siluriformes are everywhere except for the deep ocean and Antarctica (and, uh, the sky). Yet, due to human myopia, the first thing I get about catfish on Google is some weird internet mumbo-jumbo about pretending to be somebody else online? What???
Anyway, I am trying to freshen up Ferrebeekeeper, and I am going to fold the “catfish” category into a larger “fish” category (if catfish are so inexhaustibly diverse, just imagine how diverse the larger category of fish is!).
For old times sake, though, we are going to feature a few more posts celebrating the diversity of this enormous vertebrate order (1 out of every twenty species of vertebrates is a catfish!). Today we feature a little gallery of the whip slender armored catfish of the Loricariinae subfamily (aka the “whip catfish”). These small armored catfish live throughout Central America and South America East of the Andes and feed on small invertebrates of the substrate.
Rineloricaria sp. (from bluegrassaquatics.com)
Loricaria cataphracta (Compte rendu de l’expédition de Francis de Castelnau en Amérique du sud)
Apistoloricaria condei (by Hippocampus-Bildarchiv)
Aposturisoma myriodon (Image from PlanetCatfish)
Just look at all of these beauties! It is like wandering through an art show and being continuously surprised at how many stunning variations there are on a single theme.
The Amazon River is renowned for having the greatest diversity of catfish of any river—oh, and it is also the largest river in the world too, I guess. The river drains half of South America and its branches flows through many many different sorts of regions. Near Tena in Ecuador, the river’s tributaries flow through a karst landscape of sunken limestone caves, streams and springs. There, deep beneath the rainforest, scientists have discovered a catfish with a remarkable ability to climb walls—or perhaps I should say they have rediscovered a previously known fish and found out it has unexpected talents.
The cave-climbing catfish (photograph by Geoff Hoese)
A team of naturalists led by Geoff Hoese found the catfish in a subterranean waterway jauntily climbing up a sheer 3 meter (10 foot) stone wall with a thin rivulet running down it. Here is a link to a National Geographic article about the catfish—you can go there and watch a video of the catfish shimmying up and down water-slicked rocks. The scientists believe the fish is Chaetostoma microps, a member of the suckermouth armored catfish family (Loricariidae), a group of animals which Ferrebeekeeper has enthused about in past posts (although the fish’s identity remains unclear—since the team had no permit for taking specimens and left the creature unmolested still climbing its underground walls).
An illustration of Chaetostoma microps
Chaetostoma microps is not notably specialized for cave life—it still has pigment and eyes, and lacks the marked asceticism of other true underdwellers like the pink catfish Phreatobius cisternarum (which lives beneath the water table!) Chaetostoma microps feeds on algae—which is notably lacking from underground caves. So what exactly is the fish doing down there? And how/why did it evolve its remarkable ability to climb rocks without much water? The answers are unclear, but it seems reasonable to assume that a fish from the vertiginous yet cave-studded foothills of the Andes would need the ability to climb in order to maximize its habitat (and to prevent being sucked into an inescapable underground grotto). Maybe Chaetostoma microps is really a mountaineer catfish. Instead of leaping like salmon, it deals with its rocky treacherous home by suction, barbels, and indomitable spirit!
The Giant Armadillo (Priodontes maximus)
We boldly continue armor week with an overview of the magnificent armadillo family. This order of armored mammals (Cingulata) is more diverse than any other sort of armored mammals–outshining even the scaled pangolins. Today the only living members of the Cingulata order are the armadillo family (a successful group consisting of more than 20 living species) but the armadillos’ extinct cousins were once far more widespread and bizarre. These relatives included the pampatheres–long plantigrade browsing creatures covered in banded armor who roamed the continent from one end to the other. Even more impressive were the glyptodonts, massive tank-like creatures bigger than a compact car.
A fossil glyptodon, fossil pamphathere, and armadillo skeleton (in the far right corner)
The Cingulata order is part of the superorder Xenarthra. Separated from all other placental mammals for over 100 million years (due to South America’s unique isolation after the breakup of the southern supercontinent Gondwana), xenarthrans evolved in different directions from other mammals. The unique challenges and opportunities of their island continent resulted in bony domed giants like the pampatheres and glyptodonts, both of which are characterized by tortoise-like body armor composed of bone segments (osteoderms). The glyptodonts were unlike tortoises in that they could not draw their head beneath their shells: instead their heads were protected by bony caps atop their skulls. The largest glyptodonts could grow to 4 metres long, 1.5 metres high and have a mass of 3 tons (Ferrebeekeeper has already written about the smallest known Cingulata species—the pink fairy armadillo, which can still be found living in the central dry lands of Argentina).
Glyptodon
Thanks to convergent evolution the herbivorous glyptodonts resembled other armored giants like cryptodire turtles and ankylosaurs. One species of glyptodont, Doedicurus clavicaudatus, even had a heavy spiked tail (although it is unclear whether this was used against predators or to compete for territory and mates).
Doedicurus clavicaudatus
When the first members of the Cingulata order emerged in the Myocene, the top predators of South America were giant running predatory birds–the Phorusrhacidae, which resembled giant dashing eagles up to 3.2 metres (10 ft) high. The glyptodonts, pampatheres, and armadillos outlasted these terror birds and they then outlasted the carnivorous metatherian mammals (with terrible saber teeth) which followed. When the Isthmus of Panama connected South America with North America (and therefore with an entirely new universe of ultra-competitive mammals), the armored cingulatans competed just fine with the newcomers. Some glyptodonts and pamphatheres wandered up through Central America and found new homes in North America. The armadillos are still there. However at the end of the last ice-age, a new African species arrived and brought a devastating and final end to the glyptodonts, the pampatheres, and most of the armadillos. But even this newly arrived predator seemed impressed by the greatest of armored mammals. An Argentine anthropologist even reports discovering a site twenty leagues from Buenos Aires where early human hunters had used glyptodont shells as dwelling places.
Human Hunters Stalk a Glyptodon (Heinrich Harder)
A Chiton (Tonicella lokii) off the coast of California
Italo Calvino’s existential classic, Il cavaliere inesistente (“The Nonexistent Knight”) is a novel about Sir Agilulf, a medieval knight who follows the rules of chivalry with complete devotion. Unfortunately, Sir Agilulf is only an empty suit of armor: although the knight trains and stands vigils and fights in the manner of a person, there is actually nobody inside the shell. Calvino’s perplexing fable evocatively captures the workaday world where many (maybe most) people are empty “suits” who exist merely to keep a seat warm, however this predicament is nothing when compared to that of the chiton, a primitive marine mollusk covered by a row of aragonitic shells. Not only are the chiton’s rocky eyes a constituent part of its armor, the chiton itself is part of its armor! Bands of dense muscles are interwoven through the plates and sensory cells are embedded within. When the chiton dies, the shell phalanx falls apart into perplexingly shaped hunks of calcium carbonate. The remarkable segmented shells are composed of 8 plates and they afford substantial protection to the chitons which are capable of rolling themselves into armored balls. Chitons are classed as the Polyplacophora. They take their common name “chiton” from the Latin word chitōn, which means “mollusc”. The Romans derived this word from the Greek word “khitōn”, meaning tunic.
Another Chiton (Tonicella marmoreal)
Cryptoconchus porosus
For locomotion the chiton relies on its rubbery “foot”, a large band of adhesive muscles with which it crawls along the sand and rocks of the ocean bed. A chiton’s foot can produce substantial adhesion, and the creatures are able to cling to rocks with amazing tenacity. Most chitons are herbivorous grazers and eat algae, bryozoans, diatoms, and other microbes, all of which they scrape up with their sharp radula tongue–however, a few species of chiton have left the gentle lifestyle of herbivore behind and become predators. These hunting chitons trap their prey (usually small shrimp and fish) by making a box trap out of their enlarged, hood-like front end. They hold this segment of their girdle above the ocean bottom and then clamp down on unsuspecting prey which thinks they are small cavern-like rocks.
The Gumboot Chiton (Cryptochiton stelleri), the world's largest chiton!
Chitons are ancient. Fossils of stem-group chitons date back to the beginning of the Ordovician over 488 million years ago (and these lineages probably stretch back earlier into the Cambrian). Yet the Chiton’s rocky aragonite eye is comparatively recent, having evolved only ten million years ago. Chitons are hundreds of millions of years older than mammals but their eyes are much more contemporary than our own.
Pink Fairy Armadillo (Chlamyphorus truncates)
There are twenty extant species of armadillos–new world placental mammals covered with armored plates. The smallest of these armored creatures is the Pink Fairy Armadillo (Chlamyphorus truncates) which is only 9-12 centimeters in total length (about 4 or 5 inches). The diminutive creature weighs slightly more than 100 grams when mature and inhabits the central drylands of Argentina. It has multiple hard ring-like plates of delicate pink which it can close into a box form for protection (although its first defensive strategy is to dig into the ground). The animal has tiny eyes and a torpedo-like head for pushing into the sand. The portions of the Pink Fairy Armadillo not covered with plates are covered in dense white fur. Like the golden mole of Namibia, the pink fairy armadillo is a sand swimmer: the little animal agitates the fine, dry sand with its powerful claws and literally swims through the turbulence with its hard bullet shaped body. The armadillos are also like the golden mole in that they can lower their metabolism to levels unheard of among other placental mammals. However armadillos are not closely related to the golden mole—or indeed to any other placental mammals other than fellow Xenarthra (the sloths, armadillos, and anteaters). South America spent a long portion of geological time as an island and the mammals there had a long time to develop on their own. It is still not known whether Xenarthrans like the Pink Fairy Armadillo are truly Eutherians or whether they are the descendants of the ancestors of the Eutherians (sorry: the language of cladistics does not lend itself to eloquent explanations and all of the names sound like they come from a far-away planet—for example “Xenarthrans”).
I would like to tell you more about the Pink Fairy Armadillo, but I am unable to do so. Since it lives underground, the animal is rarely seen in the wild. It is even more unusual in captivity where it does not long survive the shocks and stresses of zoo living (additionally it seems unable to live on anything other than local invertebrates). This is unfortunate as it is believed that the Pink Fairy Armadillo is struggling in the wild. It is presumed to be declining in numbers–a victim to habitat loss from human activity. I used wiggle words like “believed” and “presumed” because nobody really has any idea about the actual populations of Pink Fairy Armadillos.
In the absence of real information here is a little gallery of Pink Fairy Armadillo artwork. Enjoy these pictures, it is profoundly unlikely you will ever see a real Pink Fairy Armadillo in the real world (which is sad because I find them curiously endearing). I particularly like the cartoon of the Pink Fairy Armadillo dreaming of transcendence into a mythical fairy being.
Drawing by Frohickey
Digital Artwork by Loba Feroz
Art by Guertelmaus
Sculpture by Michelle de Bruin
Cartoon by Blade Zulah
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