[leebca]

If a fish is ‘eating like a pig’ obviously, there’s something wrong. Fish aren’t pigs.

Do you think the fish eats like this in the wild?. . Ask a diver.

Why does a captive fish eat voraciously at meal time? Is it a disease? Intestinal worms? A health issue?

Let me tell you a true experience:

I obtained a dying, 2.5" non-eating tang some time back. I couldn’t tell what kind of tang it was. It was totally off-white, without markings. I knew from its general shape that it should have been one of the genus Naso, but which one only Mother Nature knew for sure. It looked like a ghost. Quite emaciated and knocking on death’s door. It had a semi-catatonic look in its eyes, a kind of cross between “I’m checking out” and “Don’t let me go.” You know that kind of look a fish can seem to give you?

I got the fish to start eating in my QT. When it did, I immediately got it eating the right kinds of foods, 3 times a day, for a herbivore, like from my post:
Feeding Marine Fish and Fish Nutrition

I declared the fish disease and worm-free and since it was eating well, I introduced it to my community FOWLR aquarium.

In approximately 10 days after getting into the main tank, the fish began to ‘eat like a pig.’ It would gulp down foods that weren't even the correct foods for it. It was eating so voraciously during feeding times that I was honestly concerned about its chances of survival. It’s belly had noticeably bulged, and against the pinched dorsal area (where fish normally store fat), the belly bulge was huge. My concern was that the fish was going to explode – literally!

I watched closely to observe its excrement. A fish’s excrement that looks like what the fish is eating has digestive problems. If you feed gut-loaded brine shrimp, the poop shouldn’t look like brine shrimp! See this thread:
Strange Excrement from Fish -or- How to be a Super Pooper Snooper

This fish’s excrement indicated it was not completely digesting its food. I re-verified to my satisfaction that the fish had no worms or microbe health issues. The conclusion was that the fish was eating too much and not allowing enough time for proper digestion of what was eaten.

During this short 10-day period of its eating frenzy, it was belligerent to other fishes in the community aquarium. A belligerent juvenile Naso you ask? Yes. It acted like all food entering the aquarium was its personal property and at meal time, in between gulping down food, it would ram or chase other fishes away from the feeding area. When not eating, it would chase fish twice its size. It even chased my Harlequin Tusk (which was pretty stupid of it). But the Tusk was, to my surprise, tolerant of the tang. Sometimes when the chase was ‘on’ the Tusk would stop and face the tang. The tang would slowly retreat.

I allowed this feeding frenzy to continue another 10 days before I took intervention action. To ‘slow the fish down’ I’d fake it out during feeding times. I’d decoy it to another part of the aquarium while dropping most the food for the other fishes at another part of the aquarium. I fed the fish algae before I fed the other fish, hoping to partially satiate its appetite. This only worked a little, since this Naso seemed to have a totally insatiable appetite. I worked on this ‘controlled’ eating frenzy for many weeks.

I continued to worry for 2.5 more months. During this time the dorsal side of the fish filled in nicely. Markings and coloration appeared slowly such that at the end of the 5 months I had a beautifully colored, orange-red lipped juvenile that was easily identified as Naso elegans.

And then the fish stopped eating. It stopped chasing the other fishes. The fish seemed almost. . .serene.

It missed a meal, then a second meal. It returned to the feeding area and nibbled at food. It missed another meal. It returned to the feeding area and nibbled at food. It nibbled at the algae. A week of this off-and-on moderate eating behavior and then the fish settled into a realistic eating pattern along with the other fish.

It ate mostly the algae sheets I offered, with some pod food now and then. It let the other food (food for the carnivores) get by. It never attacked another fish during feeding after this. It ate neither voraciously nor piggishly; instead it ate its moderate fill at each of the daily three meals. Its feces was now looking a bit sandy in appearance – indistinguishable from the food it was eating. The fish settled into this pattern and has so far continued this pattern for the last 3 years.

The experience says something to me. Why does a fish each voraciously? Why does a fish eat like a pig? The answer is simple.

A fish eats like a pig because it’s starving.

But. . .How can it be starving if it is eating so much?

I propose that Mother Nature has placed a subliminal ‘chip’ in the fish’s brain. If the fish isn’t getting the nutrition it needs, it is driven to eat more. If the fish is unsure of its next meal, it gorges itself when it can.

The fish in our aquarium is eating so much because: 1) there is something missing in its diet – the right kind of protein, carbohydrate, the right kind of fats/lipids, vitamins, elements, etc. (In short, missing one or more of the required nutrients it needs to live a healthy, long life); or 2) the fish is insecure about where its next meal is coming from (In short the aquarist is not feeding regularly); or 3) a combo of these two.

I know from this experience that a fish provided with the proper nutrients (not foods) on a regular schedule will not ‘eat like a pig.’ None of my old tank resident fishes eat voraciously. They dutifully gather at the feeding area within 20 minutes of their normal feeding time (which one has the watch I have no idea — I didn’t teach any of them to tell time ), and wait for their food.

Aquarists should review the nutrients they provide their fishes, how often they feed, and the consistency with which they provide these nutrients to be sure that ultimately, with time, their fishes don’t eat like a pig.

So having a fish that ‘eats like a pig’ may be something to be concerned about.

[Ixthys]

Originally Posted by leebca

The experience says something to me. Why does a fish each voraciously? Why does a fish eat like a pig? The answer is simple.

A fish eats like a pig because it’s starving.

Excellent info and insight.

The biggest problem I have (and many others) is not only feeding the right foods, but feeding frequently enough. I have a difficult enough time feeding twice a day...and that is a significant improvement from past years!

Anyway, IMHO I think you hit the nail on the head. The problem is modifying our behavior to fit our fishes needs.

[leebca]

Thanks Ixthys.

There are some tricks you do to stretch the meal. The algae on a clip is one way for the herbivores to graze for a few hours.

Another is to put food in a cage the fish have to pick through to get at. It gives them something to do during the day and they will get their food spread out some.

People have other ideas, I'm sure. I'll start a thread and see if we can gather up some ideas.

[dreams]

thank you!...i am having this very experience w/ my lawnmower blennie

i bought one that was eating foods offered to him.....at first, i was a little concerned because he wasn't coming out to eat.....but, after the first week he has turned into a "pig"....he swims right up to the turkey baster and hovers there, taking the food as it comes out....and never seems to be full

he appears to be in very good health, very fat....but i was still concerned about the amount he was eating

thanks for the heads up:-)

[sopranogirl]

Butterflies are picky. My pearlscale only accepts marine flakes or as I call them fish yum yums, and is only gradually beginning to accept brine shrimp. I have only over a week with it. Should I become concerned that it only and forever will only want flakes.

[leebca]

Yes. You must be concerned.

Who's in charge? You're the parent here. Let me suggest it in human terms. You have a child that only wants to eat ice cream, cake, and candy. Do you give in to that or ?

The longer the fish eats the single 'less nutritious' food, the longer it will become tied to it. Keep offering other foods; mix new foods in with the flakes; change flake brands; keep mixing things up.

Keep at it and the fish will begin to eat better foods for its long term health. Some suggestions are here:
Feeding Marine Fish and Fish Nutrition

I'm sure if you work at it, all will turn out. Just don't let the fish win by eating what isn't best for it.

[reefaquatics]

Hmmm....Interesting...

I have a true perc clown that has always been a little bit of a pig. Ive
had him for over a year and half and hes perfectly healthy. Granted hes
not like your tang...he doesnt bully the other fish..He lets everyone else
eat. I also have a Bangi Cardnal that is also quite an eater...but my fish
are not starving. I feed them twice a day a good variety of proper foods.
These two are just both a bit aggressive when it comes to food.

Plus my tank and refugium are loaded with all sorts of pods.

Good info though...thanks for sharing..

[kronos5]

Great article and very informative

[Lance]

Fish will eat themselfs to death or the need for a crain for tank transfer. Its up to you to control there diet. More food means more waste and the wrong type of food means they could be weak and vulnerable for disease. A good mix of food and smaller amounts more often works best.

[Future]

I always thought of their diet as fairly basic. Similar to Humans they eat trying to get the nutrients they need (A.k.A. something filling)
Compare the flake to lets say Chinese food, and the result is next feeding they are hungry. It fills them up for the moment, but doesn't have what they require.
Compare the live meaty foods they eat to lets say a nice pot roast. It keeps you full longer and has more of the nutrients your body needs.

When I had my Tomato Clown I used to feed flake all the time and he was always a pig about it, but when I started feeding frozen and/or live meaty foods he calmed down a lot as far as acting like a pig during his meals. He still got the flakes, but not as an everyday diet. Diversity in the foods seems like a viable remedy in that case.

[kronos5]

Good points, Lance & Future