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ancistrus7

Well, the 2016 election is finally over.  And I sort of got my wish–all three branches of government are fully united and deadlock is over. Plus we have our own Kim Jong-un now, a glorious orange child-monarch of absolute privilege who is beholden to no one and obeys no rules. Perhaps we can use this loose cannon to deal with North Korea once and for all, before they get long-range nuclear missiles or trade warfare leaves China with nothing to lose. Oh! and maybe Newt Gingrich will finally get his moon base. Anyway, we can talk about affairs of the world again in 2020 (if any of us are alive)…or maybe in 2018 if demographics moves faster than the statisticians say.

But the end of the never-ending election brings up one big problem: what is anyone going to write about now?

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Fortunately Ferrebeekeeper has the answer the nation craves: Ancistrus–the endearing  bushynose catfish!  These armored catfish from South America (and Panama) have faces so ridiculous and ugly that they are actually adorable.  Ancistrus catfish are part of the Loricariidae: armored suckermouth catfish which live on plant material.  Many of the 70 species of Ancistrus catfish live in the Amazon Basin, but some live in other South America river systems–or up in Panama. Females have a few short bristles poking out from around their mouths, but males have a magnificent beard of tendrils running from their midface.

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Male Ancistrus catfish are dutiful parents.  They hide in underwater dens and guard clutches of eggs which the females lay upside down sticking to the roof.  When the fry hatch, the father guards them when they are little and vulnerable.  Female catfish like dutiful fathers, and they are amorously receptive to males who have clutches of young (since successful males tend to have multiple batches of eggs).  It has been speculated that the tendrils actually evolved to help males look like they have young in low-light dating situations.  Undoubtedly these tendrils also help the catfish feel and taste their way around in low light situations (although the fish, like all catfish, are blessed with an astonishing array of senses).

ancistrus-cf-cirrhosus-with-fry

Three species of Ancistrus are, in fact, true troglobites: they dwell in underwater caves and have lost most of their pigmentation (and their eyes are becoming less acute and withering away).  The other species of Ancistrus are pretty stylishly colored too: they tend to be covered with yellow or white spots.  I think we can finally agree that this is a face we can all get behind!

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Greater Grison (Galictis vittata) photo by Tony Hisgett

Last week, in a throwaway post about a bizarre weasel-related mishap at the world’s foremost scientific facility, I promised Ferrebeekeeper would feature more weird and magnificent mustelids.  Today we make good that promise.  This is the greater grison (Galictis vittata), a relative of weasels and badgers which lives in the great rainforests of Central America and South America (the northern part of the continent).  Adult greater grisons weigh in at 1.5 to 3.8 kilograms (3.3 to 8.5 lbs) and range from the Yucatan Peninsula down across the Amazon Basin to the Mato Grosso Plateau.  The southern reached of South America are home to a very similar but smaller grison—the lesser grison (Galictis cuja)—which only weighs 1.2 to 2.4 kg (2.6 to 5.3 lbs).

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Lesser Grison (Galictis cuja) photo by Edward Tchementchekov

Grisons are solitary hunters which live on a wide variety of small prey, particularly small vertebrates such as fish, amphibians, birds, and rodents (but also invertebrates and maybe some larger prey when the opportunity presents itself).  Their diet is not perfectly understood, but it seems to also contain a fair amount of fruits, berries, and vegetables as well. Not only are they omnivores but they can change their schedule. Though they are largely diurnal—they can operate at night when it suits them. Likewise they are predominantly terrestrial but they can swim and climb trees with great facility.   They are clever generalists capable of living in grasslands, forests, scrublands, pastures, croplands, and mountains. Grisons live in hollowed out logs or the abandoned dens of other animals.

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Grisons are sometimes tamed when young and they prove to be resourceful and adaptable domesticated animals capable of hunting chinchillas (back when there were sufficient chinchillas to hunt).  Perhaps it seems like we don’t know as much as we might about grisons in the wild…and it turns out that such is the case.  Grisons have wide necks which taper down to narrow heads—which means that behavioral zoologists have not had much luck putting radio collars on them.  Grisons are also clever and solitary, which means that their lives are not completely understood (an unusual feature in our media saturated world). Unfortunately they do have a terrible weakness:  almost all grisons that are seen, are spotted after they have been smashed by cars.  Like skunks, and armadillos, they are particularly susceptible to being killed by cruel and indifferent motorists who will never rest till every living thing not inside a protective steel box has been crushed dead.  However South America is a big place and roads don’t go everywhere yet, so grisons are still out there, biding their time.

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photo by criadourooncapintada.org

 

One of the Aspredinidae (banjo catfish) species, Bunocephalus amaurus, from Guyana

Banjo catfish are a family (Aspredinidae) of tiny South American catfish which live in the major tropical river systems of the continent.  Most species of banjo catfish have round flat heads and long skinny tails—hence their distinctive name.  Although various sorts of banjo catfish live in many different river habitats (from quick flowing channels, to murky stagnant backwaters, to brackish tidal basins) they generally utilize the same strategy of keeping still and allowing their camouflage to protect them.  Although like all catfish, they lack scales, the Aspredinidae make up for this absence with rows of horny keratin tubercles which break up their profile and leave them well disguised.  Additionally they can shed their skins! As omnivores they hunt tiny invertebrates as well as feeding on whatever they can scavenge.  Members of the Amaralia genera of Banjo catfish are especially fond of the eggs of other species of catfish, which they actively seek out and vacuum up.

Another species of Banjo catfish (Bunocephalus coracoideus)

Perhaps because they are so partial to eating the eggs of other catfish, some banjo catfish have evolved special strategies to protect their own eggs.  Female catfish in the subfamily Aspredininae wait until their eggs are fertilized and then attach the developing eggs to their belly.  Three species of Aspredininae develop specialized fleshy stalks called cotylephores specifically for the purpose of exchanging nutrients and oxygen between the mother and the eggs.

More banjo catfish (Amaralia hypsiura)

An Aspidoras Armored Catfish

I wanted to add one final post to my armor posts of last week.  Although I posted about chitons, Chinese helmets, glyptodons, gothic armor, and Athena, I left out a post about catfish.  Ferrebeekeeper has already featured one post about the armored catfish of the Loricariidae family (an extremely large and diverse family of suckermouth catfish from South America), however there is a second different family of armored catfish, the Callichthyidae, which are characterized by two rows of bony plates (or scutes) running the length of their body. The Callichthyidae are comprised of 9 genera of catfish (and taxonomists will probably discover a few more in the future) including the Corydoras genus, which includes some of the most endearing and popular tropical aquarium fish.

Corydoras gossei (from seriouslyfish.com)

Callichthyidae literally means “beautiful fish” in Greek and the endearing little fish are common in virtually every freshwater habitat throughout South America. Some species of the little armored catfish are able to flourish in stagnant or swampy water by a unique physiological mechanism.  The fish gulp air into their intestines where the oxygen permeates into the blood vessels.  Through this fake lung they are able to survive conditions which could kill other fish and even travel overland for brief distances (although they do look rather comic expelling the air dorsally in silvery bubbles).

Callicthys callicthys (from seriouslyfish.com)

A distinctive (and extremely eponymous!) example of the Callichthyidae is Callichthys callichthys an eight inch drab catfish which ranges from Trinidad to Patagonia—an extremely large range for a little fish.   The male of this species is a bubble nester who builds a large nest out of plant parts and bubbles formed from air and mouth secretions.  Until he is perfectly satisfied with his construction he chases the female away.  Only when his nest is perfect does he let her enter: then both partners work together to defend their offspring within the little floating home.

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)

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