how long to leave lights on

[craigafrechette]

Originally Posted by Roman

If you define “snakes don’t need UVB” as “they can survive without it for an extended period of time” you are right, but actually there are several studies telling a different story.

I participated at the “Bridging The Gap” joint event of the British Herpetological Society, the International Herpetological Society and the Advancing Herpetological Husbandry FB group a month ago. I was talking to Dr. Frances Bains and Roman Muryn (both did a long lecture about lights and their effect on our reptiles during this event) about lighting for enclosures and they told me they had found that D3-levels in blood samples of snakes kept without access to UVB where extremely low compared to snakes with access to UVB. They hinted that snakes who would only get Vitamin D3 through their (rodent) diet had just enough to live on, but the level was dangerously low compared to snakes with UVB light.

There are several papers to this subject

(1) Acierno, Mark J., et al. "Effects of ultraviolet radiation on plasma 25-hydroxyvitamin D3 concentrations in corn snakes (Elaphe guttata)." American journal of veterinary research 69.2 (2008): 294-297.

(2) Baines, Frances, et al. "How much UV-B does my reptile need? The UV-Tool, a guide to the selection of UV lighting for reptiles and amphibians in captivity." Journal of Zoo and Aquarium Research 4.1 (2016): 42.

(3) Jan H. Bos, et al. “Artificial Ultraviolet B Radiation Raises Plasma 25-HYDROXYVITAMIN D3 Concentrations In Burmese Pythons (Python bivittatus)”, Journal of Zoo and Wildlife Medicine 49(3): 810–812, 2018.

to quote just three of them.

Here is a quote from (3) about the process we are talking about:

“Vitamin D3 can be obtained from the diet or photosynthesized in the skin of most vertebrates[ ]. Photosynthesis of vitamin D3 occurs when the steroid 7-dehydrocholesterol present in the skin is converted to pre–vitamin D3 via exposure to UVb radiation (280–315 nm). The most effective wavelength for this conversion is approximately 297 nm. After this initial step, the precursor is thermally isomerized over several days to cholecalciferol, the actual vitamin D3. This vitamin binds to vitamin D binding protein, enters the bloodstream, and is hydrolyzed 25-hydroxycholecalciferol (25-OH-D3), which is considered the storage form of vitamin D and is therefore used as an indicator of vitamin D status. A second hydroxylation step takes place in the kidneys and yields the bioactive calcitriol 1,25-dihydroxycholecalciferol (1,25-OH-D3), which in turn regulates Ca and P absorption. This process is regulated by parathyroid hormone.

Both have their own significant roles: 25-OH-D3 acts as a hormone and regulates the cell division by directly or indirectly regulating cell cycling and proliferation, differentiation, and even apoptosis. 1,25-OH-D3’s main task is acting as a regulatory mechanism controlling the calcium level in blood serum. Captive reptiles often have imbalanced Ca : P ratios that are likely caused by vitamin D deficiencies, renal disease, or dietary imbalance. Whether reptiles require UVb exposure to attain a sufficient vitamin D status is currently unknown. A large variety of reptile species have increased vitamin D levels following UVb exposure, and certain species actively expose themselves to UVb radiation when they have a low dietary vitamin D3 intake.”

This study took blood samples of four Burmese pythons which had no access to UVB light previously and another blood sample after 310 days of being exposed to UVB light for 11 hours per day. The pythons could move away from the UVB light, they could choose to be under the light or avoid it. One sample was insufficient, but the three remaining samples showed a six fold increase of 25-OH-D3 concentration on average (from 39 to 244 nmol/L).

So even if our snakes get enough Vitamin D3 from their food this doesn’t affect their 25-OH-D3 and 1,25-OH-D3 blood level and that’s probably the main reason why those levels are as low as we find it in many cases.

Study (1) was about 12 adult corn snakes. All of them were kept identically, with one exception. 6 snakes were kept without supplemental lighting (group 1), 6 snakes were provided supplemental lighting (group 2). For the duration of the study the snakes were not fed for 4 weeks. As in study (3) they took a blood sample before and at the end of the study from each snake. After 28 days there was no significant increase in 25-hydroxyvitamin D3 concentration in group 1. In group 2 the plasma 25-hydroxyvitamin D3 concentration increased significantly (from 63.0 ± 36.96 nmol/L to 196 ± 16.73 nmol/L). With providing of UVB the concentration of 25-hydroxyvitamin D3 triplicated within 28 days.

Both studies showed that without providing UVB the concentration of 25-hydroxyvitamin D3 is much lower as it is in the same snakes if UVB is provided. Since it is also a hormone its function is limited if the concentration is low.

Both studies state that we don’t know yet whether this poses a significant health risk for our snakes or not. But since the snakes with access to UVB increased this concentration and snakes in the wild have even higher concentrations of 25-hydroxyvitamin D3 in their blood (Dr. Baines, personal message) it stands to reason that a higher concentration is desirable and has a positive effect for the snakes whereas low levels might not have an immediate effect for the health of our snakes, but might have long-term consequences.

There are other benefits as well. UV light is anti-bacterial and anti-fungal, so it helps reducing the bacterial and fungal load of the skin of our reptiles, even helping in better/faster healing of wounds.





Craig – if we would talk about an IT issue (or any other machine) I would totally agree. If providing UVB would pose a risk for our snakes I would probably agree as well. But adding a UVB emitting fluorescent tube or metal halide lamp is neither a technical problem nor a big financial burden. The current generation of lights is safe to use if you install them accordingly (enough safety distance, heat protection etc.) and provides different levels of UVB depending on the reptile you keep. Even crepuscular or “nocturnal” animals will use them to bask during daytime, either basking with their whole body or by exposing only parts of their body.

If I know that my snakes might benefit form UVB and if it only takes (another) UVB emitting light to provide this benefit there is no question about “should I or shouldn’t I do it”. It has probably something to with our “reptile keeping philosophy”. In my experience many North American keepers have a “as-much-as-strictly-necessary” mentality (minimalistic enclosures, rack keeping), whereas many European keepers try to provide as much enrichment as possible (larger enclosures, full spectrum lights, natural look etc.). I certainly don’t want to generalize this, there are beautiful enriched enclosures in the US or Canada and minimalistic keepers here in Europe, but I think my assessment is valid anyway.

Sorry for the long rant (again), but I think this is an important issue and we can easily improve our husbandry without any major changes, just adding a light is sufficient.

I don't disagree with you. Obviously we agree to disagree. Which is perfectly fine. There's no one cookie cutter way to do things and I'm always open to learning.

I just personally haven't found that they need any specific lighting.

And although I know plenty in the States use minimalistic enclosures and racks, I personally keep all of my snakes in display enclosures and all of them are on the larger side and are setup to look naturalistic. They all have branches and clutter and opportunities for enrichment. Well, except my Borneo STP. He doesn't have anything to climb. But he's not climbing regardless.

Anyway, like I said, I'm always open to learning. And just because I don't run any specific lighting doesn't mean I never will. If enough evidence comes my way that they benefit from it I'll add it to every enclosure.

So far, over about 14-15 years I've never had a snake require a vet visit or die in my car.
All of my snakes are healthy, vibrant animals.
So I'm clearly doing something right.

But I'd be a fool to not be open to improving their care. So never say never. Just not now, it ain't broke.

[Roman]

Craig, if we ever meet in person we will probably need several days to discuss all these topics in detail…


I certainly didn’t have you and your setups in mind when I wrote about minimalistic keepers, I have seen some pictures of your enclosures and they are definitely not minimalistic. Sorry if I made this impression, it was not my intension!

I certainly tried to convince you with several papers about the subject of enrichment including usage of light, so I don’t know what other evidence you expect. Maybe you really should try some additional light in one of your enclosures and just see what happens. You don’t have anything to loose (apart from a few $$) and maybe your snakes would surprise you with a higher activity pattern…


But I agree, we don’t need to agree on everything and we certainly don’t need to derail another thread…

[craigafrechette]

Originally Posted by Roman

Craig, if we ever meet in person we will probably need several days to discuss all these topics in detail…


I certainly didn’t have you and your setups in mind when I wrote about minimalistic keepers, I have seen some pictures of your enclosures and they are definitely not minimalistic. Sorry if I made this impression, it was not my intension!

I certainly tried to convince you with several papers about the subject of enrichment including usage of light, so I don’t know what other evidence you expect. Maybe you really should try some additional light in one of your enclosures and just see what happens. You don’t have anything to loose (apart from a few $$) and maybe your snakes would surprise you with a higher activity pattern…


But I agree, we don’t need to agree on everything and we certainly don’t need to derail another thread…

Hahahhaha, well if you ever find yourself in New England I'd be happy to meet up and pick your brain.

I didn't take anything personally, no worries there.

My eyes are certainly open, and there may be a chance I experiment with additional lighting in the future.

Like you said, it can't hurt

[Andy_G]

I appreciate the information and do not disregard it and Inwill look into it when time permits. I will have to consider this when answering this question in the future, but when I consistently see snakes live decades in captivity without any UV being offered it may be a hard thought pattern to break. Thanks again for all of that.

[craigafrechette]

Originally Posted by Andy_G

I appreciate the information and do not disregard it and Inwill look into it when time permits. I will have to consider this when answering this question in the future, but when I consistently see snakes live decades in captivity without any UV being offered it may be a hard thought pattern to break. Thanks again for all of that.

I couldn't agree more

[Roman]

Originally Posted by Andy_G

I appreciate the information and do not disregard it and Inwill look into it when time permits. I will have to consider this when answering this question in the future, but when I consistently see snakes live decades in captivity without any UV being offered it may be a hard thought pattern to break. Thanks again for all of that.

I think it is a just one of those things we all “know”. It is repeated in most care guides that snakes don’t need UVB since they get their D3 from their food. Results from research suggesting something different have not (yet) found their way into the standard care guides. Since snakes are hardy enough to survive decades without supplemental UVB nobody questions the old dogma. Only if you actually read the new papers and see the difference in blood concentration with and without supplemental UVB light you start to think.

That’s why Fran Baines, Roman Muryns and others try to spread the information and why I try to argue in favor for using it here in the forum, not to argue for arguments sake but to spread the word and help to improve the way we keep our animals.

[craigafrechette]

Originally Posted by Roman

I think it is a just one of those things we all “know”. It is repeated in most care guides that snakes don’t need UVB since they get their D3 from their food. Results from research suggesting something different have not (yet) found their way into the standard care guides. Since snakes are hardy enough to survive decades without supplemental UVB nobody questions the old dogma. Only if you actually read the new papers and see the difference in blood concentration with and without supplemental UVB light you start to think.

That’s why Fran Baines, Roman Muryns and others try to spread the information and why I try to argue in favor for using it here in the forum, not to argue for arguments sake but to spread the word and help to improve the way we keep our animals.

Thank you, good sir. I've got some reading to do.

[Andy_G]

Without looking at the papers, it makes me wonder- although there is measurable difference in the level of D3 present between UVB being offered and not being offered, and if the snakes still survive for decades without it, including no perceivable detriment in regards to reproduction, does the higher level of D3 offer any health advantages, or have they evolved to operate fine without it being present? What method was used to decipher what "dangerously low" would be, and/or are there any quantitative health concern that would result from these "dangerously low" levels? Would the higher D3 levels be something that the body can utilize or produce any measurable health term benefit for the captive, either short term or long term, or have there been studies on that specifically as of yet? Just some questions that I hope the information you are going to send me will answer. If not...it would be hard to change my position to state that they "need" it after all as that would make the whole topic kind of null in my opinion. I am very much looking forward to learning more once you send me this information Roman. I appreciate that you are doing so.

[Roman]

Originally Posted by Andy_G

Without looking at the papers, it makes me wonder- although there is measurable difference in the level of D3 present between UVB being offered and not being offered, and if the snakes still survive for decades without it, including no perceivable detriment in regards to reproduction, does the higher level of D3 offer any health advantages, or have they evolved to operate fine without it being present? What method was used to decipher what "dangerously low" would be, and/or are there any quantitative health concern that would result from these "dangerously low" levels? Would the higher D3 levels be something that the body can utilize or produce any measurable health term benefit for the captive, either short term or long term, or have there been studies on that specifically as of yet? [...]

Andy: I was talking to Dr. Frances Baines and Roman Muryns during a conference in May for (literally) hours about this whole topic lighting and it’s consequences for our reptiles. That was when she mentioned this “dangerously low concentration” in the blood samples she found. So I don’t know what concentration of D3 would actually be harmful. But just to give you a better understanding whom we are talking about I just post her speaker profile from the upcoming event in the US in September (which is the first conference of the AHH held in the US and the spin-off of the event I participated in May) -->https://www.ahhconferences.com/ If you can make it to this event it will be most likely an even better “eye-opener” for you!

“Dr Frances M. Baines

Frances qualified from the University of Cambridge School of Veterinary Medicine, “many years ago”. Now retired from veterinary practice, she has spent the last 15 years researching the use of specialist lighting in the husbandry of reptiles, amphibians and more recently, mammals, birds and invertebrates. She is an appointed Advisor to the British and Irish Association of Zoos and Aquaria (BIAZA) and to the European Association of Zoos and Aquaria (EAZA)’s Animal Welfare Working Group.”

So I suppose it is safe to say that she knows what she is talking about.

Just look at the results. For the corn snakes the plasma 25-hydroxyvitamin D3 concentration tripled from ca. 63.0 nmol/L to 196 nmol/L within 28 days. For the Burmese pythons it was a six fold increase of 25-OH-D3 concentration on average from 39 to 244 nmol/L within 310 days. Remember, the snakes could chose if they wanted to bask in the UVB light or stay in their hiding places, so this was not a UVB supplementation 24/7 but probably only a few minutes or hours per day and snake. This is the same quote from the study about Burmese pythons:

“25-OH-D3 acts as a hormone and regulates the cell division by directly or indirectly regulating cell cycling and proliferation, differentiation, and even apoptosis. 1,25-OH-D3’s main task is acting as a regulatory mechanism controlling the calcium level in blood serum. Captive reptiles often have imbalanced Ca : P ratios that are likely caused by vitamin D deficiencies, renal disease, or dietary imbalance.”

So a low level of this hormone means bone calcification runs only on a low level, leading to brittle bone structure. A nasty thought would be that this causes no problems for many breeders simply due to the fact that their snakes can’t move around and probably break their bones doing so because of their small shoe boxes they are kept in. (I am talking about large quantity breeders with tiny racks).

[Andy_G]

Originally Posted by Roman

Andy: I was talking to Dr. Frances Baines and Roman Muryns during a conference in May for (literally) hours about this whole topic lighting and it’s consequences for our reptiles. That was when she mentioned this “dangerously low concentration” in the blood samples she found. So I don’t know what concentration of D3 would actually be harmful. But just to give you a better understanding whom we are talking about I just post her speaker profile from the upcoming event in the US in September (which is the first conference of the AHH held in the US and the spin-off of the event I participated in May) -->https://www.ahhconferences.com/ If you can make it to this event it will be most likely an even better “eye-opener” for you!

“Dr Frances M. Baines

Frances qualified from the University of Cambridge School of Veterinary Medicine, “many years ago”. Now retired from veterinary practice, she has spent the last 15 years researching the use of specialist lighting in the husbandry of reptiles, amphibians and more recently, mammals, birds and invertebrates. She is an appointed Advisor to the British and Irish Association of Zoos and Aquaria (BIAZA) and to the European Association of Zoos and Aquaria (EAZA)’s Animal Welfare Working Group.”

So I suppose it is safe to say that she knows what she is talking about.

Just look at the results. For the corn snakes the plasma 25-hydroxyvitamin D3 concentration tripled from ca. 63.0 nmol/L to 196 nmol/L within 28 days. For the Burmese pythons it was a six fold increase of 25-OH-D3 concentration on average from 39 to 244 nmol/L within 310 days. Remember, the snakes could chose if they wanted to bask in the UVB light or stay in their hiding places, so this was not a UVB supplementation 24/7 but probably only a few minutes or hours per day and snake. This is the same quote from the study about Burmese pythons:

“25-OH-D3 acts as a hormone and regulates the cell division by directly or indirectly regulating cell cycling and proliferation, differentiation, and even apoptosis. 1,25-OH-D3’s main task is acting as a regulatory mechanism controlling the calcium level in blood serum. Captive reptiles often have imbalanced Ca : P ratios that are likely caused by vitamin D deficiencies, renal disease, or dietary imbalance.”

So a low level of this hormone means bone calcification runs only on a low level, leading to brittle bone structure. A nasty thought would be that this causes no problems for many breeders simply due to the fact that their snakes can’t move around and probably break their bones doing so because of their small shoe boxes they are kept in. (I am talking about large quantity breeders with tiny racks).

Thank you once again, Roman. More valuable and legitimate information.