Will A Fish Eat Until It Is Injured/dies?

[TylerFerretLord]

This is a common urban legend about about goldfish and other fish, that they will eat until their stomach ruptures. I have always dismissmed this as not true, but is it? Can anyone link me to a study or something?

I'm asking because I have accidently dumped a cup of bloodworms and one of my fish ate until its anus began to telescope out.

 

[Mikaila31]

I don't think it would be able to rupture its stomach from over eating. I've read that some of the opportunistic fish like large rainbows, can eat too much and develop problems because of it. One of my rainbows was able to swallow a whole piece of krill, he was so lucky he didn't choke on it . Your fish sounds like it might have a prolapse.

 

[OohFeeshy]

If you saw the pictures of the 'goldfish autopsy', the stomach was only really a widened area of the intestine. Not knowing anything about the structure of the walls etc, I can only guess that the intestines/stomach can expand, or if need be just start shovelling it out the other end.

 

[Colin_T]

I have never seen a fish eat until it dies and I have fed a heap of fish over the years. And I feed my fish pretty heavily. As a general rule most fish will stop eating when they are full. Fish being opportunistic feeders will eat as much as they can whenever they are offered food. Some fish like Galaxias can extend their stomachs so when they come across lots of food they can eat more.

 

[andywg]

Some predators are able to kill themselves by overeating. The most prominent example I can think of is frogfish which can eat prey so large that the prey decomposes in the stomach before being digested, thus causing the frogfish to die. In this instance large prey can refer to one single huge prey (larger than the frogfish) or many smaller prey.

 

[cheesy feet]

Some predators are able to kill themselves by overeating. The most prominent example I can think of is frogfish which can eat prey so large that the prey decomposes in the stomach before being digested, thus causing the frogfish to die. In this instance large prey can refer to one single huge prey (larger than the frogfish) or many smaller prey.

Happens in snakes too, the stomach acid builds up, if the prey item is really large, and because of the build up of pressure the snake will explode...Was on tv not too long ago.

 

[darknirvana217]

Ever watch an Asterophysus batrachus (gulper catfish) take down food. This species like expands its stomach way out, and is capable of eating things almost its size. However, like some large catfish it won't eat itself to death, but vomit up the extra food.

 

[andywg]

One thing to be considered here is evolution. What possible evolutionary advantage would be gained from eating until the fish dies? While there are occasions where infrequent gluttonous predators will eat too much (when normally they have to eat as much as possible whatever comes their way) for the vast majority of fish there is no advantage to be gained from feeding in this manner.

 

[Spider Pig]

One thing to be considered here is evolution. What possible evolutionary advantage would be gained from eating until the fish dies? While there are occasions where infrequent gluttonous predators will eat too much (when normally they have to eat as much as possible whatever comes their way) for the vast majority of fish there is no advantage to be gained from feeding in this manner.

An overeating trait would only be selected out if it leads to the death of the fish before reproduction. It is not inconceivable that the trait may exist but the natural circumstances don't come about (excess food in the wild) and so the fatal effects of the trait are not expressed and so it is passed on. A drive to eat as much of possible would be an evolutionary advantage for those who didn't eat so much as to kill themselves (due to natural scarcity), or only died after reproducing, to allow them to survive through famine periods.

An example of this would be south pacific islanders who are thought to have a predisposition to store fat, which allowed them to survive through famines after typhoons. However now it is quite literally leading to their death as with plentiful food, they are at increased risk of obesity, diabetes and heart disease. (Unsure if gene isolated)

The same would apply in a fish tank where there is relatively plentiful food.

 

[Marine/Freshwater?]

If I remember correctly some fish such as Bluefish (Pomatomus saltatrix ) eat constantly and vomit out excess food if food is available.

 

[Ludwig Venter]

Nope!!... never seen that.... Some fry eat untill their stomachs' bulge pink with newly hatched Brine shrimp, but never seen one rupture in many many years.....

 

[pastabake]

I bet its anus telescoping out was nothing more than a bloodworm being passed out. I've seen the same thing when I feed bloodworm to some of my fish.