Fattening the Fishes

There was a friend of mine who used to have some pet piranhas, back before I knew him (and back before they were illegal in our state).  In addition to the piranhas, he also maintained a colony of feeder fish, which he raised to feed to the piranhas.  He went out of town for a week or two and asked a neighbor of his to feed the fish - flakes to the feeders, feeders to the piranhas.  The neighbor got confused.  When my friend came back, he found that the piranhas had only been offered fish flakes and were all dead.

Or so he says.  This friend of mine liked his tall tales, and I'm never sure what to believe. The point is, feeding fish can be tricky.

Often, however, it isn't a question of what to feed them, but how much.  During my brief stint in the aquarium field, a few times a week I mixed up a batch of what we called "cut mix" - various fish, shellfish, and blocks of frozen krill, chopped up into various sizes - big, small, and super fine, almost powder, depending on the size of the fish to be fed.  At each tank, I was to fork over a certain amount of each - somewhere between "a pinch" and "a bit," but never "too much."

There were a select few fish, like this puffer, at the aquarium which were fed individually.  For everyone else, it was kind of a free-for-all.

I tried getting more specific feeding directions, but never got past the vague, "Oh, you know..." No, I didn't know, and it drove me nuts.  I was used to taking care of birds and small mammals, where the diet was weighed out to the gram, or of reptiles and amphibians, where you gave out so many mice or crickets, or so much salad a few days a week.  Imagine being sent to feed a tiger, and not having a clear idea of whether you were supposed to feed it a hamburger, or half a cow.  Plus, there were so many fish in each tank, I was scared that if I didn't put enough in, someone wouldn't get anything.

Invariably, I'd overfeed.

Overfeeding is a problem with zoo animals... and domestic animals... and people... but especially with aquarium animals.  You see, if you overfeed an animal, that food that is eaten is eventually going to turn into... something.  Makes sense, the more you eat, the more you poop - the difference between a tiger and a tetra is that the tiger isn't floating in and breathing in its own urine and feces (not unless you are really bad at cleaning your enclosures).  That's not even taking into account the food that doesn't get eaten, falls into cracks and crevices, and rots.

Fish are cold-blooded, like reptiles and amphibians.  Unlike reptiles, they don't have the option of soaking up some sun, basking to help speed up digestion.  As a result, they eat a lot less than we would suspect.  You've heard the adage about someone's eyes being bigger than their stomach?  With fish, that's basically accurate.  It took me a while of excessive tank and filter cleanings to figure out what was going wrong.  It certainly took me a while to get used to the idea of always erring on the side of underfeeding.

.  Knowing all of this now, if I were to go back and try again then I'm sure I would have had some cleaner tanks and a lot less leftover cut mix stinking up the kitchen (that fine-cut mix took forever to chop).  If I'd spent more time with fishes before retreating back to the safe, comfortable world of the air-breathing, I'm sure I would have eventually figured out that art of how much to feed fish