Why are superworms called "unhealthy" for tarantulas/inverts?

[natebugman]

I almost posted this in someone else's thread after I read yet another person post that crickets are better for tarantulas than superworms. I decided that it was better not to steal a newbie's thread so I started this one.

Now, the question: Does anyone have any evidence, a scientific study, sound reasoning, experience with or training in arachnid nutrition, etc, that indicates that superworms are somehow unhealthy or less desirable than crickets or roaches other than their proclivity to burrow into the substrate?

I'm not talking about what you may have heard or read about from the reptile people. Reptile metabolism and tarantula metabolism are very different. We can't just assume that what is good or bad for reptiles is good or bad for tarantulas because they sell them on the same aisle or in the same store.

So, let's hear it!

 

[Amoeba]

I've never seen any studies done but there are tables floating around reporting a high fat content in meal/super worms. A varied diet is probably best.

 

[skar]

No . . . How can you really be sure ?
I believe it's all preference . I don't use supers because I think they smell bad.
I use meal worms and they are supposed to be bad for ts . . high calcium and fat ... yet I personally have trouble believing anyone, knows the exact nutritional requirments of a large arachnid so,
I haven't had issues as of yet . .

 

[Winters]

This chart should answer some questions.

http://i257.photobucket.com/albums/hh203/Dutchology/2012/nutrition20chart.jpg

 

[Drezno]

Nobody is denying that different feeders have different nutritional content, but we can't really use those differences to determine if certain feeders are better or worse until we know more about the nutritional needs of Ts. There isn't really any scientific research available on that issue as far as I know, so I think reasonable keepers should remain "agnostic" about worms, roaches, etc being better or worse. Maybe Ts do better with a higher fat diet. Maybe the differences hardly matter since Ts are adaptable, you know? We just can't say for sure.

 

[natebugman]

I don't suppose you have a source for that chart, Winters?

If we trust that chart, then superworms are lower in calcium than crickets and slightly higher in fat. Now as people, we've been trained to think fat=bad, but can we say that in invertebrates? We worry about clogging our arteries...leading to strokes and heart attacks. Tarantulas have a dorsal aorta...no arteries, no real heart...Can the dorsal aorta become clogged? By fat? They don't even have the same kind of blood that we do. I'm no expert on tarantula nutrition. I wish I was. I know I've said this before, but, in my opinion, to say superworms are bad for T's because they have a higher fat content because high fat is bad for people is like saying to me that I should switch my mosquito colony over to Splenda because all that sugar water I'm feeding them is gonna give them diabetes.

I'm not saying high fat isn't bad for them, I'm just saying that we don't know and we should stop saying things like we do know. The one thing on that chart that does make me think that crickets might be a better choice is the moisture content. If tarantulas get most of their water from their food like we've always been told, then crickets supply more water than superworms. I suppose this depends on how the feeders were kept, but I'd buy that as logical after having squished several of both in my time.

A varied diet is probably best. I'd love to be able to switch from cricket to roach to superworm to locust/grasshopper to whatever was onsale that week, but I'm pretty limited. I can get crickets (my staple T food), superworms, mealworms (usually to small to bother with), or an occasional large moth caterpillar (expensive & T's seem to hate the texture). My wife refuses to allow any sort of roach colony and the area pet stores do not sell them. So I'm pretty much stuck with crickets and/or superworms.

 

[Winters]

I don't suppose you have a source for that chart, Winters?

I'm afraid I don't. So the information on it is best not considered solid fact.

 

[le-thomas]

This should be of some value, though it shouldn't be taken as definitive. http://www.chameleonsnorthwest.com/nutrition chart.jpg

 

[VickyChaiTea]

Well here's a chart that tells you the nutritional value for a lot of feeder insects:
http://chamownersweb.net/insects/nutritional_values.htm

So our best bet is to assume variety is best, and rotate between foods until a "perfect" feeder insect is discovered, if there is one. I mean while corn snakes in the wild eat mice, birds, bats, and small lizards they do best on an all mouse diet in captivity. So maybe the same can be said for Ts? But then again maybe not.

 

[Stan Schultz]

This chart should answer some questions.

http://i257.photobucket.com/albums/hh203/Dutchology/2012/nutrition20chart.jpg

This should be of some value, though it shouldn't be taken as definitive. http://www.chameleonsnorthwest.com/nutrition chart.jpg

Well here's a chart that tells you the nutritional value for a lot of feeder insects:
http://chamownersweb.net/insects/nutritional_values.htm ...

But all these fancy charts are not worth very much because we have no idea what the nutritional REQUIREMENTS are for tarantulas in general, or even any single species. And, this is particularly important because tarantulas (at least) have such unusual metabolisms compared to most other animals. For instance, what other animal of that size do we know of that will not only survive, but thrive, on only 4 or 5 adult crickets a month?

Back to the lab people! We gotta write another NSF grant application!


Enjoy your little 8-legged connoisseur!

 

[cacoseraph]

what Pikaia said. i think i could maybe design a hobby community experiment i could massage some data from... but really, we have almost nothign to facilitate any kind of nutritional requirement studies

 

[natebugman]

If you designed a study on nutrient requirements of tarantulas, what would you use as indicators, growth rate? Differences in the changes of length of a particular leg segment over time? Weight? Are there any other ways to quantify nutrition in tarantulas besides growth or size? The possible sources error, variation, and even the length of the study make my head begin to hurt. How do you find crickets that weigh exactly the same amounts? How do you find a superworm that weighs the same as two crickets? What if one spider won't eat as much as the others? I don't even want to think about the statistics involved with this...

Maybe I'm over-thinking this...anyone?

 

[Stan Schultz]

If you designed a study on nutrient requirements of tarantulas, what would you use as indicators, growth rate? Differences in the changes of length of a particular leg segment over time? Weight? Are there any other ways to quantify nutrition in tarantulas besides growth or size? The possible sources error, variation, and even the length of the study make my head begin to hurt. How do you find crickets that weigh exactly the same amounts? How do you find a superworm that weighs the same as two crickets? What if one spider won't eat as much as the others? I don't even want to think about the statistics involved with this...

Now you know why we have PhD candidates working pretty much 24/7/365 for 4 to 8 years just to QUALIFY to do that kind of research.

I know almost nothing about dietary research (but maybe I should, at 239 pounds!), but I think it involves keeping and carefully monitoring, or even rationing out, food consumption over a period of time. And measuring all kinds of things while doing so. And, with most tarantulas this would soon become a 25+ year project!

And, what would you measure? Everything you mention, plus a lot of things we haven't thought of. That's because you're only going to be able to do the experiment once (after all, how long do you think you're going to live?), so you have to get it right the first time. If you measure something that turns out to be irrelevant, that it's irrelevant is a publishable fact too. Sometimes failed experiments are as important as the ones that succeed! Especially when grant application time rolls around again.

And, the experiment might be characterized as a waste of time and effort except that, because tarantulas ARE so unusual among animals and are fairly tractable and easily cared for lab animals, such a study might easily shed a lot of light on our own metabolism and dietary problems.

There are all sorts of interesting questions that might be answered by such a study. For instance, why do tarantulas and humans take so long to grow and mature as opposed to other animals? What kinds of substances do tarantulas use to store excess energy? (They eat differently than we, and excrete their wastes differently than we, what makes you think they don't store excess energy in a radically different way too?) And, I'm sure that dietitians and metabolism people could come up with a lot of other, far more fundamental and introspective questions if they took an interest.

... Maybe I'm over-thinking this...anyone?

I don't think so.


So, now we have to take our little 8-legged buddies back to the lab yet again!

 

[le-thomas]

At this point, then, the key would either to be to feed your tarantulas whatever you find most convenient and available and not worry about their nutritional intake, or to give them a mixed diet in order to provide them with a decent amount of various nutrients. Since we don't know what they need nutritionally (and may never, for that matter), we sort of just have to assume that they're generalists and give them a little bit of everything, I guess.
This brings me to a question, though. Do we REALLY know that too much calcium contributes to molting problems?

 

[Greentriple]

And then you have the issue of what the little guys/gals will eat. For example, if you put in a dubia and the T ignores it but if you put in a cricket he takes it down in a blink, does that mean there are preferences...? hehehe

 

[Stan Schultz]

...Do we REALLY know that too much calcium contributes to molting problems?

I've covered this one dozens of times, and it absolutely does NOT!

Do you know that water causes cancer? If you don't believe me, consider that anybody who ever got cancer also drank water!

Same logic.

Check out my response to best food to feed crickets for Tarantulas.

Or, perform an <Advanced Search> (upper right of this page) using the search string calcium +molt. Better put on another pot of coffee or pour yourself another glass, cup, stein or flagon of your favorite beverage. It's gonna be a looooong night!


Enjoy your little 8-legged molting buddy!

 

[CleanSweep]

I've covered this one dozens of times, and it absolutely does NOT!

Do you know that water causes cancer? If you don't believe me, consider that anybody who ever got cancer also drank water!

Same logic.

Check out my response to best food to feed crickets for Tarantulas.

Or, perform an <Advanced Search> (upper right of this page) using the search string calcium +molt. Better put on another pot of coffee or pour yourself another glass, cup, stein or flagon of your favorite beverage. It's gonna be a looooong night!


Enjoy your little 8-legged molting buddy!

And yet, calcium is preached as a no no over and over again, especially on those stupid caresheets. It blows my mind that people relate their own skeleton to that of an arachnid's exoskeleton.

 

[Storm76]

And yet, calcium is preached as a no no over and over again, especially on those stupid caresheets. It blows my mind that people relate their own skeleton to that of an arachnid's exoskeleton.

It's because SO many (at least over here) will say that "reportedly" feeding high-calcium feeders WILL cause bad molts...can't say if it's true. Personally, I just vary the diet of my T's. Crickets, superworms, locusts, roaches and no whatsoever vertebrates. *shrug*

 

[cacoseraph]

At this point, then, the key would either to be to feed your tarantulas whatever you find most convenient and available and not worry about their nutritional intake, or to give them a mixed diet in order to provide them with a decent amount of various nutrients. Since we don't know what they need nutritionally (and may never, for that matter), we sort of just have to assume that they're generalists and give them a little bit of everything, I guess.
This brings me to a question, though. Do we REALLY know that too much calcium contributes to molting problems?

well, not exactly. there is tons of anecdotal evidence and even some papers that clearly demonstrate that a crickets (A. domestica, which is not the only feeder cricket in the game anymore...) only diet is sufficient for many species of tarantulas over multiple generations but we don't have nearly as much evidence for any other species of feeders. i would say maybe roaches have the second biggest body of evidence and are probably going to prove out... but i guess we will have to wait and see

 

[Stan Schultz]

And yet, calcium is preached as a no no over and over again, especially on those stupid caresheets. It blows my mind that people relate their own skeleton to that of an arachnid's exoskeleton.

First, you need to know that I'm not an electrician, but I had a stepson who was an electrical contractor, and from time to time I'd play his "go-fer" when I was out of work and he was extra busy. So, I picked up a little secondhand familiarity with the trade.

So, a few years ago I had an electrician wire some yard lights onto my house and garage because we had a prowler problem. After looking at what he was doing, I criticized him. He flatly stated that he knew what he was doing, he'd been doing it this way for 20 years! I told him that only meant he'd been doing it wrong for 20 years! At that point we decided to part company, and I got another guy to finish the job. Correctly.

Bottom line: It doesn't matter how many people say, do, or think it; or for how long they say, do, or think it; if it's wrong it's wrong. And, all those people have been wrong all those years. Real life isn't a democracy, and it doesn't make it any "righter."


Enjoy your little 8-legged philosopher!