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I was reading through a couple of old threads, and it occurred to me that there are a ton of useful posts that we will probably never see. If you remember seeing a particularly useful, or even just really interesting post from a few years ago... throw it up here.
I also found the quoted statements regarding Tomocerus to be particularly interesting.
To put the Folsomia comments into perspective, Ed quoted later that the negative effects were most likely due to the toxin that Folsomia release, which will affect small invertebrates but loses effectiveness with size and will not affect our frogs in the same way.I would love to go to NAAC and meet everyone, but my schedule doesn't allow it this year.Let me start by saying that I am just looking for interesting discussion, not trying to say anyone is right or wrong. Based on my reading, but not direct observation, I would say that we may be able to significantly improve the diets of our critters, and we can do this by supplementing the culture media and offering a nutritionally balanced food supply. Specifically, I think offering things like bean beetles, isopods and the correct springtails plus UV light may get us much further than fruit flies.
In regards to the 12 hour vitamin retention time... very cool. I guess they must get some into their joints and under their wings (or maybe they eat it as part of grooming). In regards to gut loading and nutrient modification, here is some published data(fair use).
From Oecologia 127:207-213 ...
Flies were grown on Fly medium plus supplements and then fed to wolf spiders. The supplements were: fat, amino acids, vitamins, methionine or dogfood (E-flies). The spiders were weighed weekly. The flies fed dogfood resulted in spiders more than double the size of control flies. This shows that fly food can affect fly nutritional quality.
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Next, they fed the spiders either flies or E-flies, which had been either fed or starved for 48 hours. If the effect was merely gut loading, as might be suggested, then the starved flies should be of worse nutritional quality. What they saw was that starved flies were just as nutritious as fed flies, suggesting that the nutritional quality of the flies had been altered, not just their gut contents.
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I'd also like to bring up another study on prey nutrition and a balanced diet. This is from Oecologia 119:191-197, and I think it is a really cool study. They fed the spiders either springtails, flies, aphids, spiders, fungus gnats or a mix thereof. Spiders grew very well on the springtail, Tomocerus bidentatus, which is a large ground dwelling species. They grew OK on drosophila and poorly (hardly at all) on spiders, aphids or fungus gnats. Two species of springtail, Folsomia candida and Isotoma trispinata were worse than starvation, even when mixed in with other food items. The best diet consisted of T. bidentatus and Drosophila mixed together.
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This data also makes clear that some varieties of springtail are much better than others. I alluded to this in another post. I am currently culturing another species of springtail which I beleive to be Orchesella villosa, in the same subfamily as H. nitidus, which has also been shown to be a good food. I tried to culture some Tomocerus, but couldn't get them to lay eggs.
If I ever start getting a significant number of offspring from my frogs, I am going to do a controlled study of the effects of food source on frog growth/health. Sorry about the rambling, but this is hopefully an interesting read for those of you who are bored. :wink:
I also found the quoted statements regarding Tomocerus to be particularly interesting.
