Why earthworms?

LeFarge

New member
Joined
Nov 15, 2011
Messages
182
Reaction score
6
Points
0
Country
United Kingdom
This might seem like a daft question, but... why earthworms?

What exactly is it that makes them the best staple diet for axolotls?

I am not disputing that they are the best, but like Alice I'm impossibly curious.

It seems pretty obvious that earthworms aren't the staple diet of wild axolotls in Mexico - sure the odd one might plop in but worms live in the ground, they're not aquatic (and while I'm on that subject does anyone KNOW what they DO eat in the wild).

Whenever someone asks what the best food is we hear all the possibilities (beef heart, shrimp, blood worm, chicken breast, guppies etc etc) but people take on a very strong, almost zealot-like tone about ONLY feeding earthworms and as it seems to be a pretty strong concensus I wondered if somebody could fill me in on the details.

Sorry if this has been asked before but I couldn't find a definitive answer!
 

Chirple

New member
Joined
Nov 8, 2011
Messages
319
Reaction score
11
Points
0
Location
Michigan
Country
United States
Re: Wy earthworms?

I've never heard anyone say that one should ONLY feed earthworms, although I would guess that only earthworms is probably easiest for many people since they're very easy to feed and raise.

Caudata Culture Articles - Nutritional Values
Caudata Culture Articles - Worms

They're very nutritious, so are certainly a food of choice.

I think people are more apt to caution people away from things like beef heart, guppies, and other "treat" food as they are not a terribly great source of nutrition and can cause health and digestive problems.
 

LeFarge

New member
Joined
Nov 15, 2011
Messages
182
Reaction score
6
Points
0
Country
United Kingdom
Re: Wy earthworms?

but neither of those links really has a "why" -- or addresses what an axolotl would eat in the wild?

is there any research that proves worms are the best/most balanced diet with appropriate comparables?
 

Jennewt

Administrator
Staff member
Joined
May 27, 2005
Messages
12,407
Reaction score
73
Points
48
Location
USA
Country
United States
Re: Wy earthworms?

A good staple food needs to provide calcium and vitamins, and not too much fat. If you look closely at the first of Chirple's links, these criteria rule out most of the other foods as staples. The only 3 that fit these criteria are good-quality pellets, earthworms, and some whole fish. There is no way to assess vitamins from that table, but in general the foods that provide a decent amount of vitamins are those that contain "organs" (or are fortified).

Regarding whole fish, some are better than others, so the type of fish needs to be chosen carefully. Goldfish contain a poor fatty-acid profile, so they are ruled out. Some types of frozen fish are thiamine-deficient. Homegrown guppies are actually pretty good I believe. The danger with recommending feeder fish is that people will buy them at the pet shop and they often carry disease, which is another significant issue. Given the caveats regarding fish, we are left with two reliable staples: pellets and earthworms. And then we are left with the problem of finding fresh pellets that the axolotl will actually eat. Worms then are the most failure-proof staple food.

The other reason for recommending earthworms is experience. I know of many caudates raised and bred on a diet of only worms. There aren't many other foods that one could say that about.
 
Last edited:

LeFarge

New member
Joined
Nov 15, 2011
Messages
182
Reaction score
6
Points
0
Country
United Kingdom
Re: Wy earthworms?

thank you Jennewt, that is very interesting..

I hear what you're saying about fish and totally understand... I wonder, though, if there are comps when people have fed axies exclusively on healthy fish?

I also remember as a kid (so we are going back a few decades) reading in books that raw meat should be the staple diet. I appreciate that this is now not regarded as correct, but again I wonder how axies fed on these diets have fared? Just curious.

Does anyone know what axies eat in the wild? Presumably it is quite a varied diet...?

Do wild axies have similar diets to wild tiger salamander larvae?
 

Jennewt

Administrator
Staff member
Joined
May 27, 2005
Messages
12,407
Reaction score
73
Points
48
Location
USA
Country
United States
Re: Wy earthworms?

The problem is... nobody ever does long-term feeding experiments. And if they do some kind of "experiment" with one kind of food, it's usually just one group of animals, no control group. Anecdotes are always interesting, but admittedly not very solid. Sometimes that's all we have though. There haven't really even been experiments to document what the nutritional needs of amphibians are; most of what we accept as true is whatever has been documented in reptiles, fish, or mammals.

Wild diets are almost always more varied than captive diets, in the long run. They may live for weeks on a single food though, if that's what happens to be available. Also, a wild diet can be a lot more irregular, with periods of feast and famine. I would guess that wild axolotls eat all sorts of invertebrates, like daphnia, freshwater shrimp, insect larvae, water bugs, aquatic worms, etc. And vertebrate foods such as tadpoles, their own eggs/larvae, and small fish. There may have been studies to document actual stomach contents, but I've never seen them. Their diet should be the same as tiger sal larvae, but constrained by whatever happens to be locally available, which may be different.

Old scientific studies of caudates will say that the animals were fed beef heart or liver. However, this was mostly for the convenience of the researchers. In the short term, this diet certainly does keep the animals alive and well. I did keep a group of Notophthalmus for years on a diet of mostly liver, and occasional worms. In retrospect, this probably wasn't a great diet, but it did work.

Another complicating factor is that aquatic amphibians, like fish, are probably able to absorb some calcium from the water. So dietary intake of calcium may partly depend on the amount of calcium in the water, in addition to the diet. Feeding a calcium-deficient diet may be OK in hard water, but not soft water.
 
Last edited:

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
Re: Wy earthworms?

The problem is... nobody ever does long-term feeding experiments. And if they do some kind of "experiment" with one kind of food, it's usually just one group of animals, no control group. Anecdotes are always interesting, but admittedly not very solid. Sometimes that's all we have though. There haven't really even been experiments to document what the nutritional needs of amphibians are; most of what we accept as true is whatever has been documented in reptiles, fish, or mammals.
There really isn't a critical need to develop nutritional guidelines for amphibians de novo.. it is pretty well established that in general nutritional needs are highly conserved between taxa. In addition to determine the required nutrional needs requires huge numbers of animals and each batch is given a different incremental amount of the specific nutirent (starting at 0) and each group after a specific time is euthanized and necropsied to determine the effects. This continues until the animal stops showing signs of deficiency at which the lower value is set. It also continues until the animal begins to show signs of toxicity which sets the upper limit.... So it is too expensive and not cost effective when captive institutional programs (that include necropsies) document the lack of nutritonal deficiencies....

Some comments,

Ed
 

Coastal Groovin

Active member
Joined
Nov 17, 2008
Messages
923
Reaction score
38
Points
28
Location
USA
Country
United States
You asked why earthworms? Well they are high in protein and very low in fat. They lack a hard exoskeleton that could cause impactions. They cannot hurt or attack your axolotl. You can also feed them foods rich in vitamins in turn making them a source of vitamin rich food for your axolotls.

When trying to figure out what to feed your axolotls to keep them healthy you only need to look to nature. What was originally found in the lakes with them?

The answer
1. Axolotls they just love to eat their own offspring and eggs
2. Frog eggs and tadpoles
3. Small native fishes and their eggs that were little threat to an adult axolotl
4. Earthworms washed in from rain
5. Aquatic insects and land insects that fell into the water.
6 Snails
They ate a naturally well balanced diet and that is what we should all feed our animals. I think its just comman sense to feed them a mixed as possible diet.
 

Azhael

Site Contributor
Joined
May 7, 2007
Messages
6,645
Reaction score
88
Points
0
Location
Burgos
Country
Spain
Display Name
Rodrigo
Bare in mind that earthworms can also inhabit flooded areas and can even be found in the sediment under water. Also, there are plenty more of annelids in a big lake than just "earthworms".
I think it´s highly possible that one of the main food sources for wild axolotls are crustaceans. These are largely overlooked but are an important food for almost all aquatic caudates. They probably munch on gammarids, anostraceans and likely, crawfish too.
 

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
You asked why earthworms? Well they are high in protein and very low in fat. They lack a hard exoskeleton that could cause impactions..
Earthworms are actually higher in fat than crickets. (see http://www.nagonline.net/Technical Papers/NAGFS00397Insects-JONIFEB24,2002MODIFIED.pdf ). There is also data that has been coming out in the last few years that indicates that chitin content of invertebrates has often been overestimated and that it actually provides fiber to the diet which helps with a number of things including gut motility. The whole chitin impaction argument has been around for a long time but chitin may actually only be one side of the cause as there can be other factors that are often overlooked (such as gorging, hypocalcemia, animal not used to fiber in the diet, parasites to name a few potential complications).
In other taxa, there is emerging data that indicates that food species (mealworms) long considered to be inferior to other food species (crickets, roaches) actually are a better food source than long believed by the hobby (see The effects of prey species on food conversion efficiency and growth of an insectivorous lizard - Rich - 2008 - Zoo Biology - Wiley Online Library (sorry not free access but the abstract is interesting).


They ate a naturally well balanced diet and that is what we should all feed our animals. I think its just comman sense to feed them a mixed as possible diet.
While this seems to be intuitively true, a varied diet does not mean that it is well balanced. Virtually all of the feeders used have a poor calcium to phosphorus ratio, are lacking in some vitamins or are imbalanced with respect to others (such as vitamin E to D3 and A). Captive diets also do not tend to include items that are often consumed along with prey species such as soils (which are often important sources of calcium), plant matter (which is better digested in many taxa than previously believed). Captive populations also tend to lack in some commensual/parasites that improve digestive functions (emerging data on pinworms increasing digestive efficiently in a number of taxa).

Some comments,

Ed
 

Coastal Groovin

Active member
Joined
Nov 17, 2008
Messages
923
Reaction score
38
Points
28
Location
USA
Country
United States
Bare in mind that earthworms can also inhabit flooded areas and can even be found in the sediment under water. Also, there are plenty more of annelids in a big lake than just "earthworms".
I think it´s highly possible that one of the main food sources for wild axolotls are crustaceans. These are largely overlooked but are an important food for almost all aquatic caudates. They probably munch on gammarids, and likely, crawfish too.
I fully agree with the fact that gammarids and anostracans are a major food source for juvenile axolotls. I was more thinking about adult food with my list. This past summer the main food source for my Axolotls was crayfish tail meat that I chopped and froze. In my local river I can catch 300 in 4 hours with a couple chicken wing bones. It has worked very well for me. I'm sure that small soft shelled crayfish are great meals but after they reach 2 inches they probably turn the tables and become one of the main aquatic axolotl predators native to Mexico. Presently the main predator is large introduced fish like Tilapia. Which not only eat young axolotls and eggs but compete with them for space and food.
 

Niels D

New member
Joined
Jun 2, 2011
Messages
1,215
Reaction score
34
Points
0
Location
A little village called Terheijden
Country
Netherlands
I'm breeding gammarus for all of my aquatic animals. They got in my snail culture by accident but now my newts profit from it. I agree that gammarids form a major food source, but I believe that this goes for a lot of newts.

 

Coastal Groovin

Active member
Joined
Nov 17, 2008
Messages
923
Reaction score
38
Points
28
Location
USA
Country
United States
Earthworms are actually higher in fat than crickets. (see http://www.nagonline.net/Technical Papers/NAGFS00397Insects-JONIFEB24,2002MODIFIED.pdf ). There is also data that has been coming out in the last few years that indicates that chitin content of invertebrates has often been overestimated and that it actually provides fiber to the diet which helps with a number of things including gut motility. The whole chitin impaction argument has been around for a long time but chitin may actually only be one side of the cause as there can be other factors that are often overlooked (such as gorging, hypocalcemia, animal not used to fiber in the diet, parasites to name a few potential complications).
In other taxa, there is emerging data that indicates that food species (mealworms) long considered to be inferior to other food species (crickets, roaches) actually are a better food source than long believed by the hobby (see The effects of prey species on food conversion efficiency and growth of an insectivorous lizard - Rich - 2008 - Zoo Biology - Wiley Online Library (sorry not free access but the abstract is interesting).


Ed, this came about because there were people feeding their reptiles nothing but meal worms and super worms. I have no doubt that will cause impactions but so will not having your reptiles hydrated properly. Crickets do have less fat but they are also lack almost all nutrients unless they have been gut loaded with mixed dark greens, fruit, wild flowers, bee pollen, blue green algae powder, pumpkin, etc. I have seen threads on here talking about crickets causing impactions. I personally think that is crazy. I feed mine animals crickets and lobster roaches all the time but I mix up their feeding with garden worms and a long list of soft grubs and insect larvae so I never worry about it.



While this seems to be intuitively true, a varied diet does not mean that it is well balanced. Virtually all of the feeders used have a poor calcium to phosphorus ratio, are lacking in some vitamins or are imbalanced with respect to others (such as vitamin E to D3 and A). Captive diets also do not tend to include items that are often consumed along with prey species such as soils (which are often important sources of calcium), plant matter (which is better digested in many taxa than previously believed). Captive populations also tend to lack in some commensual/parasites that improve digestive functions (emerging data on pinworms increasing digestive efficiently in a number of taxa).

Some comments,

Ed
I feed my animals garden worms that have plenty of soil on them so that is not a problem for me. Since I also gut load all my feeder insects before they are offered to my animals so I don't worry about them lacking any vitamins In the summer my animals get wide variety of wild collected insects like camel crickets, June beetle larvae, grasshoppers, pill bugs, moths, maggots, bess beetle larvae, centipedes, green inch worms, black field crickets, this way anything if I miss anything gut loading I have that covered. The best part its all free!!!!
 

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
Ed, this came about because there were people feeding their reptiles nothing but meal worms and super worms. I have no doubt that will cause impactions but so will not having your reptiles hydrated properly. Crickets do have less fat but they are also lack almost all nutrients unless they have been gut loaded with mixed dark greens, fruit, wild flowers, bee pollen, blue green algae powder, pumpkin, etc. I have seen threads on here talking about crickets causing impactions. I personally think that is crazy. I feed mine animals crickets and lobster roaches all the time but I mix up their feeding with garden worms and a long list of soft grubs and insect larvae so I never worry about it.
There is a small iota of truth to this and a lot of stuff that has been floating around the net about gut loading for more than 20 years and turned into nothing but dogma..

Gutloading was (and technically still is) the practice to maximize the calcium content of the feeder invertebrates.. the hobby has rebranded it to mean any diet fed to the invertebrate that is believed to enhance the nutrition of the feeders. Very little of this has been subjected to a hard analysis to support it...

First off... do you have a reference that documents the nutritional value of crickets before and after feeding all of those supposed goodies?..

That crickets are devoid of nutrients unless fed that kind of gut load isn't supported in the literature; we can see that (as one example) in the nutritional link I referenced above.. Actually any basic diet that supplies carobohydrates, protien and moisture will "optimize" the cricket..(see for example the nutritional chapter in Mader's Reptile Medicine and Surgery) there isn't any indication that feeding them greens must improve the nutrient quality of the cricket... (other than anecdotal testimony which is called into question by some analysis..) or that the carotenoids are passed along in any appreciable level.. (and aren't simply digested..)

As for roaches.. that superfood has it's own issues... If the roaches are fed a high protein diet, then they store the surplus as uric acid.. which then has an impact on thier nutritional content (see http://nsrdec.natick.army.mil/LIBRARY/59-69/R65-43.pdf for example).. In this case the uric acid is absorbed and excreted by the kidneys and if the levels are sufficiently high, we can see damage resulting in kidney disease and the formation of kidney stones...

There is a huge amount of unsupported hype that has been passed around by various hobbys until it has become dogma..

Some comments,

Ed
 

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
Ed what do you feed your insects then?
It depends on several factors.. First off I make several distinctions, the first is between microfauna established in the enclosures and those housed in backup cultures, the second is between feeders that are a routine part of the diet and those that are only occasionally fed out to the animals.

There are several reasons for this.. the first is that many invertebrates sequester tocopherols (vitamin E), and the level of this can potentially be many times that found in the food (see for example
Draper, Harold H.; Philbrick, Diana P.; Agarwal, Sanjiv; Meidiger, Roy; Phillips, John P.; 2000; Avid uptake of lineolic acid and vitamin E by Drosophila melanogaster; Nutrition Research 20(1):113-120)..
The levels stored by the invertebrate can be sufficient to disrupt uptake of vitamin A and D3 as these three vitamins compete for uptake. So in cage and routinely used feeders need to be fed a diet that doesn't result in excessive storage of vitamin E (this means for example, fish flakes, dog food, cat food, nuts and many seeds are not ideal) in the invertebrate, So for example I feed mealworms corn flakes as this has a low but stable level of tocopherols and I provide water via carrots and potato slices..
For crickets, I use either slices of orange or hydrated polyacrylamide gels (not high calcium) for water. For the food, again, I use corn flakes or other modest tocopherol grain based food. Two days before I feed them out, they are fed a high calcium (ground rodent blocks) high vitamin A diet (since hypovitaminosis of A is widespread in at least anurans) before feeding them out. This reduces tocopherol storage and helps slightly with the calcium and A.

For fruit flies, I use Repashy Superfly media (although I used to mix my own).

All feeders are dusted with Repashy ICB, or Superpig at each feeding. I also introduce astaxanthin or superpig every so often into the enclosures for the microfauna as those carotenoids are also taken up by the arthropods (astaxanthin in particular). Many larval amphibians can metabolize astaxanthin to a second form of retinol (while poorly if at all converting beta carotene) which is used in growth and development (and vision). It is found in the eyes of at least adult anurans where it is found in oil droplets allowing vision further into the IR end of the spectrum.

For those that are housed in the enclosure with the animals, I offer astaxanthin or Repashy Superpig, pieces of fruit, vegetables and calcium carbonate (either via Rep-cal without D3) or via clay substrates. They also get to scavenge any dust that falls into the enclosure.

For those that are only occasionally fed out, (such as one of the 5 types of isopods I culture) I offer them fish flakes, potato, cardboard.. since the frequency at which they are offered isn't sufficient to disrupt the uptake of those vitamins.

When using a dusting supplement the ratio of A (not in the form of beta carotene (beta carotene does not count) to D3 to E should be as close to 10 to 1 to 0.1 as possible.

Some comments,

Ed
 

Coastal Groovin

Active member
Joined
Nov 17, 2008
Messages
923
Reaction score
38
Points
28
Location
USA
Country
United States
I don't believe that man made vitamins are as effective or safe as feeding your insects high quality greens and fruits and don't use them.
 

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
I don't believe that man made vitamins are as effective or safe as feeding your insects high quality greens and fruits and don't use them.

Based on what evidence? There is no evidence that a synthetic form of D3, or retinyl palmitate/acetate or even tocopherol functions any differently in the insect or amphibian.

In addition, feeding of "greens" does not supply vitamin A in the form of a retinoid but as beta carotene which in other taxa of amphibians is either poorly converted or not converted at all....

Ed
 

Azhael

Site Contributor
Joined
May 7, 2007
Messages
6,645
Reaction score
88
Points
0
Location
Burgos
Country
Spain
Display Name
Rodrigo
plant matter (which is better digested in many taxa than previously believed)
Could you elaborate a bit on this (in another thread if you see it fit)? I admit to adhering to the dogma of plant matter being pretty much worthless for caudates and if this is wrong i´d love to learn more.
The latest thing i had heard of that made me doubt the dogma was about plant matter contents in feeder invertebrates and how those represented a valuable nutrition source in the pressence of the invertebrate´s digestive flora.

Sorry for taking up your time.
 

Ed

New member
Joined
Nov 6, 2001
Messages
3,578
Reaction score
18
Points
0
Location
Bridgeton, NJ
Country
United States
Could you elaborate a bit on this (in another thread if you see it fit)? I admit to adhering to the dogma of plant matter being pretty much worthless for caudates and if this is wrong i´d love to learn more.
The latest thing i had heard of that made me doubt the dogma was about plant matter contents in feeder invertebrates and how those represented a valuable nutrition source in the pressence of the invertebrate´s digestive flora.

Sorry for taking up your time.
Well I had typed a long explanation but it got eaten somehow since I have a couple of things to do I'll come back and retype it..

Ed
 
General chit-chat
Help Users
  • No one is chatting at the moment.
  • (Guest) Taro Tea:
    I just got this new axolotl and I didn't cycle the water because the pet store guys said I didn't have to but now I know I have to
  • (Guest) Taro Tea:
    Will anything happen to my axolotl??
  • Mother of Dragons:
    keep adding prime everyday for a week and your axolotl should be ok
    +1
    Unlike
  • Chat Bot:
    Guest guy has joined the room.
  • (Guest) guy:
    hey
  • sde:
    Caudata.org chat? Haven’t seen this in years
    +1
    Unlike
  • Dougie:
    @sde, hi everybody I'm getting a tiger salamander coming from Katy Texas what are the shipping conditions that's okay to have them shipped to me in the state of Vermont it's just starting to get the temperature low above 45 but it may be too hot to ship him any thoughts or ideas on how to work this out
    +1
    Unlike
  • newtmember:
    as long as its not freezing they should ship fine. I usually ship mine in 2 days priorities like axolotl. insulation and some cold pack. Is this morphed or still a larvae?
    +1
    Unlike
  • macmac194:
    Greetings I have a quaratined tiger salamander due to not feeding and feeling lethargic. I saw a slimy green stuff inside the enclosure. Is this vomit? Poop?
    +1
    Unlike
  • Jjrio421:
    Are you still looking to rehome any of your axolotl babies?
    +1
    Unlike
  • Chat Bot:
    Guest nagato has joined the room.
  • (Guest) nagato:
    Does anybody know where or who to buy danube crested newts from?
  • Mother of Dragons:
    Anyone in the DMV area looking for juvenile axolotls? I have several morphs available. Experienced owners and pickup only please.
    +1
    Unlike
  • Chat Bot:
    Guest axmaolotl has joined the room.
  • Ariania Lee-Ann:
    I currently have a 3 year old axolotl, he hasn't been eating for the past couple of weeks and has lost a lot of weight. Hedwig usually eats bloodworms and earthworms just fine but now he won't even stud it. I've done a water change to make his nitrate lower and his water is at a good temperature
    +1
    Unlike
  • Chat Bot:
    Guest zippy has joined the room.
  • (Guest) zippy:
    what substrate is he on?
  • Linkisnotzelda:
    Are any of you guys on Quora? I’ve started an axolotl space there and am looking for people interested in helping out!
    +1
    Unlike
  • KarateKid08:
    I am wanting a spotted or tiger salamander and I was wondering how often to feed, what the best feeders would be and how many fed per feeding session.
    +1
    Unlike
  • Chat Bot:
    KarateKid08 has left the room.
    +1
    Unlike
  • Chat Bot:
    KarateKid08 has joined the room.
    +1
    Unlike
  • newtboi:
    Can I has alpine newts pls
    +1
    Unlike
  • ndbug:
    Any ambystoma breeders looking for californiense
    +1
    Unlike
  • axolotl owner2020:
    does anybody have any information on homemade baby axolotl food?
    +1
    Unlike
  • axolotl owner2020:
    I have an earthworm farm, and a tight budget.
    +1
    Unlike
    axolotl owner2020: I have an earthworm farm, and a tight budget. +1
    Top