Ultimate UVB Topic
Posted 03 November 2002 - 06:15 AM
Light is generally considered an electromagnetic wave.
Wavelength is measured in Nanometers (1/1000000000 meter)
IR is 700nm - 1500nm
Visible light is 400nm - 700nm
UVA is 320nm - 400nm
UVB is 286nm - 320nm
UVC is 200nm - 286nm
VUV is 100nm - 200nm (vaccuum UV)
Window glass through at least 50 websites I reviewed tonight, ranging from hobbyist, manufacturers to collegiate physics presentations on the web all agree that there isn't a significant amount of UVB light passed through. The problem with this statement is that the majority of sights just take this as common knowledge and move on. A few sites refer to the state of the energy. I will give a quick explanation
Light hits a "transparent" object, if the energy level of the light matches it doesn't pass through. Glass lets through light that is above 350nm in general. This is to say that a lot of the light is absorbed or reflected, but what I can't find is how much is absorbed and reflected.
At this point it requires a major study of the chemical make-up of glass and the intensity of the light and a bunch of heavy math that I am not really capable of doing at this time.
What I have discovered through Melissa Kaplan's fine site Anapsid.org is a couple of charts that give us a breakdown of natural sunlight and things it pass through
A single pane window should transmit about 5% UVB, modern double pained windows will allow about half that, if they're tinted even less. If the light goes through a screen or a tank wall cut even more. So with single pane window with access to direct sunlight for part of the day you get the same output as a reptisun 5.0 bulb at 12 inches away.
Now onto some theories....
Barb Reader has had Timmy the Cooter for nearly 43 years. He started as a dimestore turtle. For the majority of Timmy's life he has had just window light. From Barb's story it took Timmy several years to reach adult size.
I have had Uzumaki the Cooter for 8 months. He has had a Reptisun 5.0 bulb on for 14 hours a day, which he usually sits about 5 inches away. My turtle started at 1.75 inches and is now 4.5 inches. At his current rate of growth he will be a full grown adult this time next year.
My theory is that the turtles grow a lot faster when subjected to longer and more regular UVB exposure. The amount of UVB given off by the light and the assumption that the window was single paned is close, just the actual amount of time the turtle is exposed differs.
So is this form of accelerated growth good? normal?
Anybody have a turtle before these new crops of lights came out and has gotten one since and noticed this?
Posted 03 November 2002 - 08:25 AM
The first point: to reach maturity in size, it has to do with time. I mean if we feed a human the best foods and optimal condition, it's still going to take 16-20 years for a male human to grow to it's full size. If someone grew up with a lot of sun, that would say they would reach adulthood quicker? Hmmm. [
The second point is the better nutrition (Ca and Vit D), the better the growth (i.e. bigger and stronger bones/shell). This is taken as a fact in most literature in the field (Ca + VitD = strong bones & bigger), but not necessarily maturing faster.
I think you are mixing up point one and point two. I think your cooter will be bigger in the end and healthier with the better source of Vit-D from UVB. But it will still take 'X' number of years for your cooter to reach maturity. No matter how much UV and nutrition it gets. All this does is make it bigger and stronger, but does not make it grow faster.
What you do think Michael?
Posted 03 November 2002 - 08:42 AM
In humans, we have found that better nutrition leads to both taller growth and earlier puberty. I am pretty sure the sun is not a factor, but remember that we, too, need D3 for growth, and in colder climates it is often added to milk so that we get it even in the absence of sufficient sun exposure.
Posted 03 November 2002 - 05:17 PM
This is getting to be an even more popular theory withthe Eastern Species of Box Turtles. Most of these animals very rarley sun themsevles and live in forests with thick canopies.
while I personally agree that we should do the UVB anyway it just gives us something to think about!!
Posted 04 November 2002 - 01:54 AM
Also another factor is the food that is fed to the turtle. Reptomin now is a probably a lot better than pelleted foods that were available in the 60s. I can't quite remember what Barb said about what Timmy was fed when young, but her current diets are excellent. But it seems to me that humans and other animals grow a lot faster when they are provided with more nutrients and the means to metabolize those nutrients.
We hear a lot about people making their tortoises grow too fast. However the tortoises get pyramiding and shell deformities. But is this the result of just too much protein/fat or is it that their isn't enough calcium/d3 metabolizing going on at an equivalent rate.
For simplicity lets say that a tort needs a ratio of 2protein - 4calcium to maintain a slow even growth. Now lets say we increase the protein intake with dogfood. Lets assume that dogfood is 12protein - 8calcium, this gets the turtle to maturity 6 times faster, but with deformities. Is it concevable that if the tort was able to metabolize the 12 protein and 24calcium that it would grow normally but 6 times faster? So to increase the amount and duration of UVB should raise the metabolization of calcium, making said turtle grow faster, without deformity.
***Please note - this ratio is a theoretical argument and in no way should be considered as a good ratio for tortoises, please review your species care requirements.
I believe that any studies into this would be cruel, so I guess we'll never really know, but I think that over-abundance of UVB light helps turtles grow faster.
Posted 04 November 2002 - 02:02 AM
This talk of animals accquiring the vitamins and minerals through diet is good. But UV light gets to the surface in even heavily forested places and it even gets through clouds. So I believe that box turtles are still getting some/enough UV to metabolize their needs. While raising your baby, I bet he will grow a lot faaster than his wild counterparts for 2 reasons, abundance of food and abundance of UV light. Even with shade in a turtle pen, it'll get more direct light than in the woods...
Also on anapsid.org in one of the articles they did some tests with lizard basking spots. cold bright place vs. warm dark place and the lizards always chose the bright place, somewhat proving that the reptiles instictively knew how to regulate their UV exposure.
Posted 04 November 2002 - 02:06 AM
Posted 04 November 2002 - 08:32 AM
Posted 04 November 2002 - 12:07 PM
Timmy was not fed 'ant eggs' which was the common form of turtle food at that time. My father got something called, "quick green flies' which was combined with lettuce, and knowing my late mother, it was probably iceberg lettuce. However, in addition, I loved to catch insects and feed them to Timmy and Jimmy, and was pretty much always digging for worms and chasing files and grasshoppers. For all I know Timmy wouldn't be here today without that.
On the UVA/UVB front, Timmy and Jimmy shared a room with my sister (b. 1950) and me (b. 1955). They lived in what is today called a 'death pond' for their first year or six months before being moved to a 10 gallon tank. They lived there until they were about 1/2 as wide as the tank, maybe a little more. I think this was in 1965. That is when my father and I built a built-in out of lumber coated with boat epoxy. There was no sand, and if either had been female, that turtle would certainly have become egg-bound and died, but one of my books at the time said that turtle eggs didn't HAVE to be laid, and could be held in the turtle indefinately to no ill effect.
In the early years, the turtles had no filter, but we changed their water either every other day or daily. Once in the 10 gallon tank, they had a basking platform made out of half a textured garbage can, with a door cut into it so they had a hide box. They had not basking light except the sunlight streaming in the window. The room had an Eastern exposure, and caught the morning sunlight. The tank was not kept covered, and frankly, I can't figure out how they survived.
After they were moved to the built-in, they still had no filter, but at some time over the years I added a basking lamp and a clear pastic cover to keep the set-up humid. The cover gradually got dirtier and dirtier, and was never cleaned. However, the sunlight came in through a pane of plexiglass which was next to the window.
Most of the windows in my parent's house had storm windows attached, as well as screens.
I wish I could claim better husbandry for my wonderful turtle, but I can't. I read everything available to children at the time, but those books were pretty bad (I still have most of them.). When I entered high school, and took a summer science course in which I was to conduct an experiment, I sought to do it on turtle nutrition, but was told I had to use eschirica coli. (That's spelled wrong, I know; They are one-celled critters). Timmy and Jimmy might have been far better off if I had read the mid-70s scientific data on turtles, but instead I read on e. coli.
That's the had truth. I wish I could claim better care.
Posted 04 November 2002 - 12:23 PM
MichaleT, YOu may try looking onto some Reef lighting equipment. Certain things kept by saltwater hobbyists require this true day/night cycle. I've heard of equipment they use to replocate this.
Posted 04 November 2002 - 11:59 PM
Posted 17 November 2002 - 05:53 PM
even our best UVB sources don't come close to the suns output
given enough to eat and good health wild turtles should out grow captives every time
reptiles grow through out thier lives (starting fast then slowing down)
the speed of which can be effected by the care given
the age an animal reaches maturity can not be change
mamals work differently than reptiles so can't be used to compare
example: human females start thier period for the first time at 105 lbs and about 17% body fat
age has nothing to do with it
the high fat diet that brings on early puberty also lets to longer adultleses
the easyest way to simulate the changes in light levels would be to have many lights on timers
i had more but i've forgotten now and don't want read back through at this time
got a im going on the side and i keep typing the wrong stuff on the wrong thing, maybe later
Posted 18 November 2002 - 01:19 AM
So if a girl never reaches 105 lbs she will never have a period. Would you care to share your sources, becuase this sounds pretty farfetched.
Also, the comment was about the availability of nutrients and the means to metabolize them, and mammals, fish, reptiles, single celled organisms all follow the rule that more = faster and bigger
I think the point is that the animal will get a sustained 5% UVB in an indoor setup for 12-14 hours. The suns UVB flucuates depending on hundreds of variables and time of day. I think the actual amount of absorbed UVB is in the indoor setting.
Wild turtles almost never outgrow captive turtles. In fact I have never heard of a case of this. My comments towards Billy's hatchling is that he will get regular and knowing Billy excellent food and not have the ability to hide in the deep dark forest. Meaning that his growth rate will far exceed a wild hatchling on its own.
Posted 18 November 2002 - 07:40 AM
Here is the link http://www.zoomed.co..._univ_test.html Now I have not been able to verify this test with Boston University. I have emailed their staff a couple of times and have received no response. Others have complained about this too! So there is no verification on what ZOOMED claims!.
Also it is not necessary to understand the physics of optical transfers. You only need to measure the outputs using a "UVB Meter". That is the final say because all else is just cheap talk and cheap theory until verified with lab equipment! Here is a link for some tests done using a "UVB Meter"...http://www.reptilesdownunder.com/reptile/enclosure/uvlighting.html[8D]
Posted 18 November 2002 - 07:57 AM
Originally posted by MichaelT
I've ben thinking on ways to simulate a true day night cycle. Does anybody have any ideas about this. Was thinking of lights that move from one side to the other and that the intensity goes up til afternoon then starts to fade. I believe this would be even better than just a heat and strip light...
Michael, I believe it would be futul to attempt this. Since the intensity/power of the sun is pretty strong at high noon. There are medical grade tubes out there that can generate this amount of UVB.
On the order of 250 Uwatts/CM.
Very easily you can damage the eyes of the reptile (and your own) with these high power tubes. Also being medical grade tubes and very specialized I would imagine they are prohibitively expensive.[
Posted 18 November 2002 - 08:11 AM
Posted 19 November 2002 - 03:43 AM
yes, ther are 98 lbs women out there with children
msot 98 pounders have unuasal cycles, baring the use of the pill or other meds
the human body gose through many changes at that time
the % of lean/fat mass and bone is one of them
there are other factors in this too, childhood stress being a big one
but none of this has to do with turtles
metabolize = production of energy, the side effects of which is what people talk about irl (growth,body heat, burning fat)
reptile metabolim is different than a mamal that's the point i was trying to make
Posted 03 December 2002 - 11:44 PM
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