Nathan's MITy Aquarium

Species

Colomesus asellus "South American Puffer", "Amazon Puffer"

Background

There are six freshwater "South American" or "Amazon" Puffers (Colomesus asellus) in my 55gal aquarium. The pictures here and the fish are both courtesy of Randal in Chicago. The puffers were originally collected in Peru (not by Randal), but i've also seen them for sale locally as "Bumblebee puffers". Unlike most puffers, they are a completely freshwater species, and will remain healthy without the brackish or saltwater that most puffers require.

If you've never seen a fw puffer cruising around seeking something to eat, looking for all the world like a search and rescue helicopter with twin searchlights swiveling, you are missing out. Puffers have more personality and are more "cute" in their pudgy, awkward looking way than any other fish i've kept.

Photos


Isn't she cute?

20021123 - Update: With the help of a borrowed digicam, i've captured some photos and video clips that demonstrate some of the personality of these critters.
More photos:
Thin fish, Fat fish, Full fish, School fish.	Hi fish, Joe fish, Tube fish, Low fish.
Blowfish

Diet

For the first couple days none of them acted interested in food, although the little brown pond snails that seem to invariably smuggle themselves in somehow, and in this case probably hitchhiked in on the Java Fern or Green Hedge, all disappeared. Puffers are excellent at curing a snail problem! After a couple days, two of the puffers started eating the flake food offered. The others began to grow scrawny (there's nothing quite so pathetic as a scrawny puffer fish), and i tried Cichlid pellets and tiny bits of raw beef (for lack of the anything better). A couple more decided they'd eat if "Beef: it's what's for dinner", and it was comical no end watching them worry the bits like a dog, trying to bite off chunks small enough to swallow, or "help" each other out by tugging at the other end of the bit of meat.

It's important to note that the two lone snails that i saved in a separate bucket with lettuce and flake of their own will (hopefully soon) provide an essential addition to the diet when they have multiplied to sufficient numbers. A puffer has a specialized "beak" or teeth that must be worn down to prevent it from overgrowing and preventing the fish from eating, much like the teeth of rodents. In the wild, this is naturally accompished as the puffers eat their usual diet of crunchy snails and shellfish. In the aquarium, they will need similar foods.

20021123 update: After further observation, it appears that the puffers don't really chew much on the snails, but rather pick them out of the shell and then leave what's left alone. I bought a block of frozen krill at the LFS to give them something chewy, and the puffers seem to like them:

Videos (Compressed with the free Divx codec to avoid modem hernias)

Eating flake food

Eating krill

Behavior

The two puffers that began to eat first were also the two that spent less time attacking their reflection in the back, right corner of the tank and cruising up and down and back and forth, all the while pushing against the glass like they were trying to escape. They began instead to wander inquisitively around the tank, looking (apparently) for even more to eat. They never seem to think they've had enough, for even when their bellies are bulged out like little balloons, they still hunt and beg for more. When they see you watching them, they will come forward and "beg" for another flake fix. The others are still acting a bit weirded out, but i believe the chance of them starving is diminished now that they have found something they will eat.

The previous keeper encountered problems with the aggressiveness of these scrappy carnivores. In spite of the assertion in most available species catalogs that the Amazon Puffer is the most peaceful and least territorial puffer, the fish were nipping their tankmates. The platy and danios that share their space in my tank haven't lost any limbs or turned up missing yet, but i haven't tested the puffers' self restraint on a smaller or long-finned fish yet. They have been remarkably docile with one another, a trait that is truly remarkable in a puffer species.

20021124 update: Although they continue to coexist completely peacefully, even obliviously, with one another, they still persist in attacking their reflection on occasion. I haven't figured out what sets it off, but it seems to be more common when they've just eaten a lot, or when they're scared (ie i just put my hand in the tank to replant another poor ambullia stem, broken off by the previous spasm from the puffers).

I wrote too soon that none of the tankmates have lost any limbs. One of the agile and incessantly moving danios was somehow a victim of a nasty fin nip later that week, leaving him with just a nub of a tail fin. Fortunately, the fin has completely regrown, allowing him to frolic once again, instead of waggle awkwardly around. More seriously, a couple otos have lost eyes before they learned to move when a puffer starts eying them. It was tense for a bit, but everything seems to have settled down now.

Videos (Compressed with the free Divx codec to avoid modem hernias)

"Ya' wanna make something of it?"

"C'mon, are you chicken?"

"So, you think you can take me, huh?"

20030131 update: *&%# puffers... after a much-needed cleaning when i returned from Christmas break, i returned to the tank to find the most aggressive puffer viciously attacking a Danio, which was already too far gone to do anything for. I'm still not sure why the puffers get so psychotic when their environment changes, but this is getting ridiculous! There is also one less Oto in the tank than there was before i left, but nobody is talking. Chalk up two more fish outlines on the casualties list.

Armed with a gift certificate to Boston Tropical Fish and Reptile that my thoughtful aunty gave me for Christmas, and after observing that 'Motley', the Platy, is the only fish the puffers have left alone, i added a new male Mickey Mouse Platy (called 'Mickey', uninspiredly enough) and also a Bala shark, which is fast enough and big enough that i assumed it would be fine. Big mistake. The beautiful high dorsal of the Bala was nipped severely a few days later. I'm hoping it will be an isolated incident and will grow back like the Danio fins did.

The Ambullia i added a couple months ago has finally been eliminated. The puffers constantly broke it up with their hysterics, and the low light levels didn't help any. I added a Crypt. wendti with the two new fish. It's supposed to tolerate low light....

Links

Further information can be found here, on the page that helped me identify the species.
The aquarium main page