PDA

View Full Version : What do axolotls eat in the wild?


Silver
13th February 2012, 21:23
In the wild, axolotls probably don't eat worms (except for the odd few that might accidentally wind up in the lake). What do they eat? I'd like to feed Levi as natural a diet as possible (I was thinking shrimp), but I thought I'd check here first :D

Chirple
14th February 2012, 06:38
There was a thread that had a very good outline of this a while ago, but I'm sorry that I've forgotten which one it was.

Shrimp, though, are not a good source of nutrition and their shells can be difficult to digest.

I would caution you that "what they eat in the wild" is not necessarily what you should be feeding them. There's a reason why wild animals have a drastically shorter life expectancy than those in captivity and diet is a big reason.

In the wild, many species of animal do not eat ideal diets, what is available might lack necessary nutrition, be difficult to digest - to the point of deadly impaction. This is a natural part of life in the wild, but not something people generally want to subject a cared-for domestic pet to.

Just think - what did human animals eat "in the wild ? Our life expectancy was very short back then and it was only with development of tools and weapons and social structure that we started to flourish and take off and enjoy longer, safer lives with a more stable and rich diet.

I think your heart is in the right place, but with a diet informed by science and research, you can help your axolotl grow to its full health and potential, something they would not likely get in the wild. :)

I really recommend earthworms as a staple - they're nutritious and easy to digest and you'll get to see your axolotl hunt the bits down and shake them and look very satisfied with itself after catching them. :) Blackworms are also nice and provide a hunt as well.

I have some shrimp in my tank, because I think they're cute and fun to watch - but they don't get eaten very often at all. My axolotl is not interested in them unless they're holding something she more readily identifies as food and she ends up eating them in the process of trying to get what they're holding - be it a blackworm or a pellet. Sinking pellets are nice if you get appropriate ones. I have some big ones I use as part of her main diet and some small ones for "treats".

Silver
15th February 2012, 21:03
Thanks, Chirple! I had always thought wild animals had a shorter life expectancy because of predators and what not, but you definitely make a good point. I love naturalistic tanks, but I want my axie to have a nice, long life. When I can get earthworms again, I'll stick with those!

Azhael
15th February 2012, 21:34
While itīs very true that wild animals have shorter lifespans and that food is one of the factors i donīt think the problem lies on nutrition, but rather on availability of food. There are specialist animals with diets that are quite poor nutritionally but they have adapted their physiology accordingly to obtain all they need (koalas spring to mind). They wouldnīt survive otherwise, and there wouldnīt be any activities that are energetically costly, like courting. If animals in the wild can spare lots of energy at certain times itīs because they are healthy and fit, their diets cover all their needs. You may get a specific individual or population that for some reason has a restricted diet compared to normal conditions and that may even wipe them out, but that wouldnīt be the norm. A wild animalīs diet is pretty much the perfect diet.
A more likely issue in a wild diet is parasite loads. Some parasites could be a critical factor in shortening lifespans in the wild.

Anyway, sorry for the rambling.

As for a captive axolotlīs diet, earthworms really are the perfect staple. Even in the wild, annelids may represent a larger portion of the diet than youīd think as there are many aquatic species and even more typical "worms" can inhabit the underwater sediment.
Shrimp, as long as they are a fresh-water species are a great addition to a varied diet as many other crustaceans are. Crustaceans very likely represent a good portion of their natural diet too. You can also offer waxworms, crickets, small fresh-water fish, woodlice, and even pellets as part of the diet.

Chirple
15th February 2012, 23:30
O, I would agree for the most part - I was also thinking of the problems that Lake Xochimilco has been having for a long time. Nature is unstable. And I do think that if physiology is taken into account, we can improve on nature's diet, random mutation and natural selection only gets you so far !

I also caution against, "they sometimes eat small fish in the wild, so I will give them feeder fish" because, of course, you're dealing with a lot of variables and using tropical or Chinese fish, so it's not really what they'd get "in the wild", though I'd be curious to know how such fish compare.

Jennewt
16th February 2012, 01:40
Here is the thread where I recently made some wild speculations about what axolotls eat in the wild. And there is a lot of other good info there about captive nutrition.
http://www.caudata.org/forum/f46-beginner-newt-salamander-axolotl-help-topics/f48-axolotls-ambystoma-mexicanum/f57-axolotl-general-discussion/81727-why-earthworms.html

caleb
16th February 2012, 09:21
There was a recent study which examined stomach contents of wild axolotls:
http://limnology.wisc.edu/personnel/jakevz/pdf/2010_Zambranoetal_BiolInv.pdf

They found the contents to be (with approximate percentage by volume):
Chironomids 20%
plants 20%
small crustaceans 15%
particulate organic matter 14%
unidentified insects 11%
fish 7%
algae 6%
zooplankton 4%
other invertebrates 3%

The high amount of plant matter and organic debris is rather striking- about one third of the total stomach contents!

There's also been another study recently examining food preferences of axolotl larvae, but I've only seen the abstract:
ingentaconnect Feeding behaviour of larval Ambystoma mexicanum (http://www.ingentaconnect.com/content/brill/amre/2011/00000032/00000004/art00008)
I'd be interested in seeing this if anyone has access to it.

Greatwtehunter
16th February 2012, 09:56
The high amount of plant matter and organic debris is rather striking- about one third of the total stomach contents!

Wouldn't the majority of it just be due to incidental ingestion?

caleb
16th February 2012, 11:48
Wouldn't the majority of it just be due to incidental ingestion?

I would have thought so, I was just surprised at the large amount. Most other studies on urodele stomach contents seem to find relatively small amounts (or don't even mention it).

lollypop
16th February 2012, 21:00
Mine deliberately eats plants. :o

Syllvie
24th March 2012, 03:35
I would caution you that "what they eat in the wild" is not necessarily what you should be feeding them. There's a reason why wild animals have a drastically shorter life expectancy than those in captivity and diet is a big reason.

I disagree; while science is pretty awesome, there's no replacement of what an animal is naturally designed to eat. The reason animals live so much longer in captivity, is because we don't allow them to get eaten by other predators, we make sure their food is free of any diseases, and we keep their areas cleaner than they would be in the wild.

Of course, I study Canids, and not Amphibians. But, using dogs as an example: 99% of dogs are descendents of the Grey Wolf. Grey Wolves eat the meat of prey they kill themselves. The only recorded findings of Grey Wolves eating plant matter, turned out rather ugly(plants cause them to throw up). Not that throwing up is a bad thing at all, but obviously they aren't eating it for its nutritional value. Some people try to say that Grey Wolves eat the stomach contents, but that isn't true. If the prey is large enough, they simply rip open the stomach contents and eat the lining of the stomach, but leave the contents and the intestines alone. They do eat the stomach contents of SMALL prey(rats, birds, rabbits, etc.), but even that is still a very small percentage. Using these scientific findings, a lot of people (like myself) feed their dogs what's known as the Prey Model Raw diet. In other words: We feed raw meat to our dogs. Many raw-fed dogs live to be twenty years or older; almost twice the lifespan of dogs that are kibble-fed. So, again, while science is amazing, it can't always produce a meal as nutritional as what it would get in the wild.

That being said, I do agree that, in the case of Axies, a captive-version of their diet would be better than what they might eat in the wild. I don't know the types of insects, plants, and fish are in the lake; and I'm not even sure I'd be able to find them even if I did know. I think worms are about the best we can do for them. (:

Caleb - That's an awesome find. Perhaps we're a little closer to improving our captive-bred Axolotls' diets even more!

Lollypop - My carnivorous dog also voluntarily eats a certain type of weed-grass. I have no idea what it is, but it's the only grass he eats. I assume he likes the taste. He also enjoys carrots, cheese, and bread. Unfortunately, he can't have wheat anymore because he's allergic to it. ):

knifegill
25th March 2012, 08:11
Just think - what did human animals eat "in the wild ? Our life expectancy was very short back then and it was only with development of tools and weapons and social structure that we started to flourish and take off and enjoy longer, safer lives with a more stable and rich diet.

This is untrue. Once we began farming, our stature decreased, our teeth began to rot out and our brains became smaller. Humans do thrive best on a diet comprised primarily of game animals (fat, organs, bones - all) and vegetation. Humans lived just as long back then as they do now, but the high rate of infant and child mortality brought the average numbers down. Modern hunter-gatherers are our best portrait of wild human life, and they make it into their eighties and nineties easily once they escape the dangers of youth and predation. Meanwhile, modern people eating artificial food and hiding from the sun are dying in their fifties and sixties of easily preventable conditions. Captivity shortens our lifespan by about 30% after accounting for the threats we've overcome.

limnologist
13th May 2014, 04:57
I disagree; while science is pretty awesome, there's no replacement of what an animal is naturally designed to eat. The reason animals live so much longer in captivity, is because we don't allow them to get eaten by other predators, we make sure their food is free of any diseases, and we keep their areas cleaner than they would be in the wild.

Of course, I study Canids, and not Amphibians. But, using dogs as an example: 99% of dogs are descendents of the Grey Wolf. Grey Wolves eat the meat of prey they kill themselves. The only recorded findings of Grey Wolves eating plant matter, turned out rather ugly(plants cause them to throw up). Not that throwing up is a bad thing at all, but obviously they aren't eating it for its nutritional value. Some people try to say that Grey Wolves eat the stomach contents, but that isn't true. If the prey is large enough, they simply rip open the stomach contents and eat the lining of the stomach, but leave the contents and the intestines alone. They do eat the stomach contents of SMALL prey(rats, birds, rabbits, etc.), but even that is still a very small percentage. Using these scientific findings, a lot of people (like myself) feed their dogs what's known as the Prey Model Raw diet. In other words: We feed raw meat to our dogs. Many raw-fed dogs live to be twenty years or older; almost twice the lifespan of dogs that are kibble-fed. So, again, while science is amazing, it can't always produce a meal as nutritional as what it would get in the wild.

That being said, I do agree that, in the case of Axies, a captive-version of their diet would be better than what they might eat in the wild. I don't know the types of insects, plants, and fish are in the lake; and I'm not even sure I'd be able to find them even if I did know. I think worms are about the best we can do for them. (:

Caleb - That's an awesome find. Perhaps we're a little closer to improving our captive-bred Axolotls' diets even more!

Lollypop - My carnivorous dog also voluntarily eats a certain type of weed-grass. I have no idea what it is, but it's the only grass he eats. I assume he likes the taste. He also enjoys carrots, cheese, and bread. Unfortunately, he can't have wheat anymore because he's allergic to it. ):

I noticed and just thought id let you know, I did a bit of research on canids myself (now im into limnology and herpetology). The grass the dog is eating is probably water grass (common weed) and they eat it when they have an upset stomach.

limnologist
13th May 2014, 05:01
This is untrue. Once we began farming, our stature decreased, our teeth began to rot out and our brains became smaller. Humans do thrive best on a diet comprised primarily of game animals (fat, organs, bones - all) and vegetation. Humans lived just as long back then as they do now, but the high rate of infant and child mortality brought the average numbers down. Modern hunter-gatherers are our best portrait of wild human life, and they make it into their eighties and nineties easily once they escape the dangers of youth and predation. Meanwhile, modern people eating artificial food and hiding from the sun are dying in their fifties and sixties of easily preventable conditions. Captivity shortens our lifespan by about 30% after accounting for the threats we've overcome.

People still have no idea how unhealthy grains are for the human being. Cow milk is very unhealthy as well. A diet made up of meat, carbs from vegetables like potatoes and bananas, and raw, fresh greens is the natural diet of the human. No grains needed. The only reason grains are such a large part of our diet history is because it is easy to grow and keeps fresh, feeding would-be starving people in the earlier times.

limnologist
13th May 2014, 05:04
O, I would agree for the most part - I was also thinking of the problems that Lake Xochimilco has been having for a long time. Nature is unstable. And I do think that if physiology is taken into account, we can improve on nature's diet, random mutation and natural selection only gets you so far !

I also caution against, "they sometimes eat small fish in the wild, so I will give them feeder fish" because, of course, you're dealing with a lot of variables and using tropical or Chinese fish, so it's not really what they'd get "in the wild", though I'd be curious to know how such fish compare.

I thought common feeder fish (goldfish, rosy reds, platies, guppies) all had a chemical in them that inhibits the use of vitamin B in herps?
I know for a fact that such feeders differ greatly biologically to the natural fish in the axolotls' habitat. they are more fattening for sure and have fewer of the vitamins that the axolotl has adapted to obtain. What are the native fish of the lakes? maybe someone can start breeding them.

Boomsloth
14th May 2014, 01:58
I thought common feeder fish (goldfish, rosy reds, platies, guppies) all had a chemical in them that inhibits the use of vitamin B in herps?
I know for a fact that such feeders differ greatly biologically to the natural fish in the axolotls' habitat. they are more fattening for sure and have fewer of the vitamins that the axolotl has adapted to obtain. What are the native fish of the lakes? maybe someone can start breeding them.

Goldfish are what contain thiaminase an enzyme which breaks down thiamin (Vit B). Guppies and minnows are fine. From what i've read it seems that the axolotl used to live with only smaller fish that it could eat, and until the introduction of tilapia and larger aggressive fish it was the apex predator in those waters.