Throwing up half digested food?

[AshSeek]

I'm not sure which of my three axolotls is doing this, i assume its either my pink lecuistic or my light wild type, because my dark wild type has not ate as much as the others, i just got her so she is still adjusting.

two days ago one threw up a feeder fish and some worms. and the next day another feeder fish appeared (they have had feeder fish before and have not thrown them up). today, none of them ate this morning when i tried to feed them which is not uncommon, sometimes they are hungry and sometimes they aren't. when i came back within an hours time, there are more regurgitated worms in the entrance of their hide cave.
last week i was gone for about 3 days and they did not eat worms, but this has happened many times and they have not thrown up before.

The only other time my axolotls have thrown up food was when i was transporting them in the car for an hr ride to my college. and i never feed them before i transport them since.

Should i be worried or what can i do to help them keep it down?

[EmbryH]

I would say that either something is stressing them out, perhaps temperature fluctuations, or they're just eating too much so they vomit.

Do you keep feeder fish in the tank on a regular basis? I've had some axies eat worms, then eat some feeders and throw up when their stomachs got too full.

Are there any signs of stress on your axies? Is your water quality good? As long as you don't see curled gills/tails, any other signs of stress, and your water is good, I'd just suggest removing any other fish and try regulating how much they eat a bit more strictly in order to avoid overfeeding.

[AshSeek]

i technically have a tank warmer in there but its at 68 degrees Fahrenheit, normally it would be 72 degrees or warmer without it so i figured at least it will stay a few degrees cooler and stable temp.
not sure on water perimeters, i'm not really big on checking them. their tank just got cleaned and refilled a week and a half ago, that was when i came back from winter break so i'm sure their tank is still cycling, i never mess with it tho and never had before and they still never had that problem, not to say its not causing it this time.

Feeder fish are not kept on a regular basis i just buy some once in a while.
tails are not curled and most always their gills are foreword, sometimes they are not but all gills are large and healthy looking. i don't really think mine curl their gills with stress, as they have always been that way, like it seems to be how they like to hold them, even before they started throwing up food.
thank you for the help :)

[EmbryH]

I'm unsure what you mean about the heater... are you suggesting that an aquarium heater keeps your tank cooler than without?

Do you have a tank thermometer?

Also you should test the water conditions in this situation.

[AshSeek]

yes that is what i meant about the heater, sorry for confusion.
my thermometer currently says it is just about or below 70.
i'll see if i can test it soon.

[Elise]

Can you take some pictures of your axolotls and post them also?