Reptile & Amphibian Forums

I have just been in the process of changing my lighting in my tank and i have been doing a lot of research on types of lighting available. I have been concerned about whether or not to use lighting with UVB or not. I have in the past but I have come across a lot of research that leads me to believe that is not the best thing for some amphibians and their eggs development. i typed "amphibians uv" into my search engine. I found many links concerning this issue. Very interesting. i would like to know what others feel about this issue and if anyone has any information concerning the effects of UVB exposure to darts and their eggs. here is a bit of an article to get it started.

"We found that some species are very sensitive to UV radiation in the field and by using field experiments we've found that eggs would die under ambiance UV-B rays," Blaustein said. "The mortality rate is correlated with a certain enzyme."

That certain enzyme is photolyase, which neutralizes the harmful effects of the sun's ultraviolet rays. The radiation has been proven to cause various cancers and genetic defects.

Hays said there is almost a 100 fold difference between the species with the lowest and the highest levels of photolyase.

"What we've shown is that there is a differential sensitivity of embryos to ultraviolet radiations," Kiesecker said. "Some species are sensitive and others are resistant."

Researchers noted that low photolyase levels also led to increased fungal infection rates for amphibians. Just like a bacterial or a viral infection, the fungus pathogen can kill an amphibian.
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0.4.0 D. leucomelas
0.0.4 D. auratus(grn/blk Panama)

DAPTF

DECLINING AMPHIBIAN POPULATIONS TASK FORCE
Link

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0.4.0 D. leucomelas
0.0.4 D. auratus(grn/blk Panama)

I didn't read the link below, but the information you have posed seems like a logical conclusion. I have never understood some people's fixation on supplying UV rays to their frogs in the first place. While a little bit of it MIGHT help metabolize calcium (however, that's why Rep-cal is fortified with D3), the extremely thin skin of frogs seems like it should be very susceptible to pass-through radiation.

Eggs, especially, have no pigmentation to absorb (i.e., block) the damaging effects of ultraviolet radiation, which is a known carcinogen and mutagen, particularly in situations where DNA is directly exposed to its full effects. Thiamine dimers are just one of the spontaneous mutations that often take effect when exposure to UV radiation occurs over a long period of time. After all, UV lamps are used in a lot of aquarium setups to kill microorganisms.

I understand that many of us here have learned that UV is good, and even necessary, for the healthy development of many reptiles. However, you have to realize that the integumentary system of reptiles is far more developed than an amphibian's, allowing for UV to be absorbed without affecting the lower basal cells and internal organs.

Perhaps someday someone will come up with a properly dosed amount of UV that is actually found to be beneficial for darts, but it doesn't sound like a good idea to me right now. I'm not about to cook my frogs by placing them under a UV bulb less than 2 feet from them for 12 hours per day. That kind of exposure should be left to rednecks in tanning parlors.
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense

The issue here is the wavelengths. The germicidal bulbs produce UVC. UVC doesn't penetrate our atmosphere and as far as know is not produced by any reptile bulb. Also those reptile UV bulbs don't produce a hole lot of UV in the first place and according to my vet (he is a doctor of herpitology with UF's small animal clinic) they are shot in about 4 months.

You can over dose an animal on D3 by feeding it to them, but if you provide UV thats not a risk.

Look, no offense, but your reasoning shouldn't be "so and so told me this, so it's right." You come up with faulty conclusions when you don't understand the full logic behind it. It's good to ask others for advice, but don't go hanging your hat on someone else's PhD . . . especially when a lot of people around here, including myself, have a background that includes graduate training in molecular biology and genetics.

That said, I have to take issue with your statement that "UV is not a risk." Frankly, that's a clinically silly statement.

First, I understand that modern water filtration units USUALLY use UVC radiation because it allows higher sterilization percentages at a faster gpm rating. It's not because UVA and UVB have no mutagenic, carcinogenic, and radicalization effects. Any insinuation otherwise is unfounded. Second, you also need to understand that most UV radiation is going to be reflected by your glass top (and, to a lesser extent, by acrylic tops for those of you who use those).

So, why would you want to be using UV bulbs anyway? Sure, I understand that most reptile bulbs are not going to have a high output of UV, but there are those around who are looking at using LED's which produce a higher amount of UV for calcium uptake. Dosing that is going to be much harder than dosing D3, no matter how you cut it. So, I'll take my chances with fat soluble vitamin toxicity in my frogs from a reasonable dose of supplementation before I start foolishly relying on UV bulbs for the same effect. Too little, no effect. Too much, you might as well put them in a microwave. That was my reasoning behind the above post. I wasn't trying to attack anyone . . . I was just trying to be a tad (pun intended) humorous with the redneck joke.
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense

Sorry if I came off ignorant. I was trying to use him as a qualified source for the iformation rather then joe shmoe at the pet shop. I have yet to find one pakaged with information on its useful life and I have heard they produce an adequte amount of UV for up to a year. However, the manner in which he came to his 4 month figure is the most sound I have heard yet and is the reason I accepted it(don't ask me to repeat it because I'm not nearly as knowledgeable on the subject as him). Kudos on having graduate training but like you said a lot of us do around here. Mine is in plant ecophysiology.

Also I wasn't trying to suggest that UVB wasn't mutagenic or a danger in anyway. Your right that would have been silly. I was just suggesting that the amount produced by any reptile bulb wasn't enough to do much of any damage (which you seem to agree with).

What was try to say with the D3 thing, is that if you are using UV on the frogs so they can produce their own D3 there is no risk of over dosing because they can regulate its production, but if it is being fed to them they can't regulate the quantity they recieve or expell any excess (at least this is how I have come to understand it).

I think we just had a simple misunderstanding. I just felt like you were trying to refute my statements by using parallel arguments that really didn't address my points. That typically raises my ire, especially when it's a simple matter that really shouldn't be open to debate. I think I just read you wrong.

As for the D3, your point is well taken about vitamin toxicity. However, I still feel that it is too difficult to regulate an appropriate amount of UV to know with certainty that enough D3 is being produced without the possibility of causing potential long-term effects through deleterious effects of the radiation (after all, even low doses for 12 hours per day for 15 years can be harmful). There are just too many variables involved (especially with the 4 month life of UV emission that you have indicated--probably dropping off intensity from the first use) for most of us to even be interested in attempting to provide UV for calcium metabolism reasons. Of course, that's my opinion, but I think it's pretty well reasoned.

Anyway, no intention to call you ignorant. I could tell you weren't ignorant from the post about pothos that I read later this morning. I just thought you were trying to pick a fight over nothing. I misunderstood. No hard feelings.
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Homer W. Faucett III, esq.
Purveyor of Trivialities and Fine Nonsense

I apologize for the missunderstanding. I realy wasn't trying to pick a fight at all. I have had a head cold recently and things sounded good and well reasoned when I first posted them, but upon looking back I was not making my point well at all. That is completly on me.

there is some very interesting documentation concerning the rapid decline in the amphibian population and the increase in embryo fatality and mutations. Up until about the last ten years most of the decline has been blamed on deforestation and urbanization. where in actuality when amphibians are concerned majority of their decline has been related to the deterioration the the environment, ie. ozone and acid rain. I was reading one site and they were saying amphibians are like the canary in the mine of sorts. they are a great way of telling how the deterioration of our environment may effect the human race.
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ss
0.4.0 D. leucomelas
0.0.4 D. auratus(grn/blk Panama)