Do skinks REALLY need u.v?

[trogdor1988]

That answers it then, for the most part alot of you breeders have done so without u.v and not come across any complications as long as there well cared for in other areas of there life. As they should be anyway, hmm might get me a few skinks now haha.

 

[Bluetongue1]

I am not quite sure how you can have a conversation about the need for UV light and not mention Vitamin D3. This is an important area but not one well understood. Here’s my two bob’s worth – hope it helps.

[FONT=&quot]The role of Vitamin D3[/FONT]
Vitamin D3 enables the body to absorb calcium from food as it is digested in the gut. It also allows the body to metabolise calcium e.g. incorporating Ca into bones to strengthen them, using Ca to allow muscles to contract and relax, using Ca in nerves so that they can conduct nerve impulses and many other functions. Calcium is so critical that the body will take it out of the bones if the level in the blood begins to drop for any reason.

SUMMARY: Calcium is a critical mineral in the body. Vitamin D3 is required to absorb and make use of Ca from food. The body needs BOTH to avoid becoming calcium deficient.

[FONT=&quot]Sources of Vitamin D3[/FONT]
UVB light drives a chemical reaction in the skin of vertebrates in which a form of cholesterol is converted into the pre-cursor for Vitamin D3. The body can then easily convert this pre-cursor into active D3.

Diet is another source of Vitamin D3. This is one of the fat-soluble Vitamins and it is therefore primarily stored in the fat globules in the liver. So liver (raw) is the richest natural source of Vitamin D3. Vitamin D3 can also be purchased in powdered form and administered as a dietary supplement.



Animals that eat whole vertebrates get a rich source of both calcium and Vitamin D3 e.g. snakes, most monitors. So even though elapids and monitors bask, they do so for heat only and don’t need the UVB. More omnivorous animals, such as many dragons and skinks have difficulty under natural conditions in getting sufficient Vitamin D3 from dietary sources and so compensate by producing it in the skin with exposure to UVB.

Young animals that are growing fast have the highest demand for calcium, primarily to provide bone growth. So they also have the highest demand for Vitamin D3. Once fully grown, calcium and Vitamin D3 needs are minimal as the animal simply needs to maintain its bone density.

Metabolic Bone Disease (MBD) is a broad term that refers to a general condition. There can be various causes and varying complications, depending. Common causes:

1. Diet deficient in calcium (whether there is adequate D3 or not)
2. Insufficient D3 (whether there is adequate calcium or not)
3. Kidney disease in which calcium is continually excreted.

There are some other, less common conditions that metabolically block the use of calcium and so have the same net effect as calcium deficiency.

 

[Tassie97]

hypotheticaly then if you took a blue tongue out for natural sun for an hr or two a week would that be suficiant uv for a baby blue tongue or will powders and lights needed?

 

[K3nny]

i've kept asian rainbow skinks with UV, and took my bluey out for sun now and then + he seemed happy with it, liked the warmth and all
for the garden skinks it's more of a better safe than sorry thing, but i do find they tend to run about way more then when i don't give em anything + sunning a skitish skink aint good for the nerves
I've also seen wild ones in my backyard basking... yes, basking (although for what reason i have no idea, it ran before i could ask )

apparently the theory goes that since they have iredescent/reflective-like skin, it's questionable if any UV actually penetrates them at all and therefore if they get any benefit from it
rainbow skinks are a prefect example of this, since their skin reflects rainbow-like colours when it get's hit by light i.e. the full spectrum of red orange yellow etc

 

[KaotikJezta]

I had a very healthy blue tongue for years without UV and my EWD was only given UV after coming on this forum and totally freaking out about MBD. When I first started keeping EWD's back in 2002 nothing I read said they needed UV and the few things that did mention using it suggested 2.0 at the most. My EWD is a robust healthy 4 year old girl I have had her for 3 years without the slightest issue.

 

[-Peter]

All the experts come on here and talk about how "I haven't supplied this and I haven't done that" but not one of them backs it up with any proof other than "I dont reckon its had any adverse effect".
How about some real proof. Bone density studies for a start. Un-metabolize calcium levels.
If you do not supply a method of D spectrum vitamin metabolism you are not looking after your animals. Its as simple as that.

 

[KaotikJezta]

Peter, when I said nothing I read said you needed UV for EWD, I was talking about books written by 'experts'. All my animals have UV lighting now, like I said, when I first bought EWD's general consensus was they needed very little to no UVB.

 

[Bluetongue1]

i've kept asian rainbow skinks with UV, and took my bluey out for sun now and then + he seemed happy with it, liked the warmth and all
for the garden skinks it's more of a better safe than sorry thing, but i do find they tend to run about way more then when i don't give em anything + sunning a skitish skink aint good for the nerves
I've also seen wild ones in my backyard basking... yes, basking (although for what reason i have no idea, it ran before i could ask )

apparently the theory goes that since they have iredescent/reflective-like skin, it's questionable if any UV actually penetrates them at all and therefore if they get any benefit from it
rainbow skinks are a prefect example of this, since their skin reflects rainbow-like colours when it get's hit by light i.e. the full spectrum of red orange yellow etc

The properties of light in the visible spectrum and the behaviour of light in the UV spectrum, with respect to transmission, absorption and reflection vary dramatically. A simple example, 95% of UV light is absorbed by typical 3mm window glass, yet most visible light is transmitted. However, at an incident angle of around 20% window glass will reflect most light in the visible spectrum.

Basically, what you are saying about iridescent colours and highly reflective scales does not mean UVB will be reflected.
Blue

All the experts come on here and talk about how "I haven't supplied this and I haven't done that" but not one of them backs it up with any proof other than "I dont reckon its had any adverse effect".
How about some real proof. Bone density studies for a start. Un-metabolize calcium levels.
If you do not supply a method of D spectrum vitamin metabolism you are not looking after your animals. Its as simple as that.

Are you saying that people insist that that you MUST supply UVB or else?

If that is the case, I agree that this isn’t necessarily correct and is certainly incorrect for a lot of animals. So long as there is a source of Vitamin D3 then UVB can be done without in many cases (assuming in both cases that dietary calcium intake is sufficient).

There is clear evidence to date that UVB exposure (and sufficient calcium) can reverse the effects of MBD of stripping calcium from the bones, resulting in a marked increase increased in bone density. I wonder how it would go if dietary Vitamin D3 alone were used? Maybe MBD reduces (indirectly) the body’s ability to absorb and utilise Vitamin D3 from the gut? I don’t know but it would be interesting to find out.
Blue

Peter, when I said nothing I read said you needed UV for EWD, I was talking about books written by 'experts'. All my animals have UV lighting now, like I said, when I first bought EWD's general consensus was they needed very little to no UVB.

As best I can ascertain, an hour or more three times a week in natural sunlight, somewhere between late morning and early afternoon, is adequate for bluetongues and shinglebacks.

 

[K3nny]

The properties of light in the visible spectrum and the behaviour of light in the UV spectrum, with respect to transmission, absorption and reflection vary dramatically. A simple example, 95% of UV light is absorbed by typical 3mm window glass, yet most visible light is transmitted. However, at an incident angle of around 20% window glass will reflect most light in the visible spectrum.

Basically, what you are saying about iridescent colours and highly reflective scales does not mean UVB will be reflected.
Blue

true, doing spectrophotometry i actually got the whole nitty gritty from my lecturer, most boring topic ever... anyway, back on topic, i'm merely quoting what the supposed theory behind it was, not necessarily true as you've pointed out, especially with the invisible spectrum area (which granted is quite wide of a range, humans are rather limited sight wise)
yet another reason why i go with the better be safe than sorry school of thought, we simply don't know enough yet to claim otherwise. Yes some don't appear to need it but that's almost a superficial observation, internaly we just have no idea.

an experiment like kaotikjezta would probably help shed light (pun not intended) into the topic, if there was anyone who could bother with said experiment that is

although, i wonder why skinks in particular (several species that is) have reflective scales compared to like for example, agamids? Another thing to possibly look into.

 

[Bluetongue1]

I know what you mean about the physics of light – the only thing that gets excited are valence electrons!

As best I can ascertain, there has not been a lot of experimental work done on D3 in reptiles and it would seem almost zero in Oz. However, the yanks have done a little. The following gives a bit of info which I reckon has applicability to a lot more species than just the Green Iguana. Worth a read: http://www.anapsid.org/pdf/jody-hibma-uvb.pdf. The following article is a little more technical but summarises the work done to date (1996) on D3 and UVB and gives a whole list of references to the source material. Sunlight and Reptile UVB Tubes

Blue

 

[ianinoz]

Lizzy loves basking in bright sunlight on the bricks surrounding my front patio and flowerbed in the afternoon.

The bricks were sometimes cool to touch when she was doing this , so she is probably after the UV.