quad eggs not hatching (lack of pre-formed vitamin A?)

It seems like the more experience I have with keeping quads, the worse my hatch rate becomes. In fact, the last 2 clutches of quad eggs (from different LTC females) I incubated went full term but failed to hatch. Some slit their eggs, others simply sweat, shrunk, then died. Even the ones that slit their eggs failed to exit their eggs. It seems like they were simply too weak to survive. Incubation (1:1 ratio of vermiculite to water by weight) at 70F was the same as other clutches I've hatched. Strange thing is, the more experience I feel I have (since the mid 90s with quads) the less success I seem to have. Here's my theory. Any feedback would be much appreciated.

With montane species in general I think I may have gone to the extreme in avoiding pre-formed vitamin A. As a subscriber to the Chameleon Information Network in the early 90s, one article in particular caught my attention. The editor before Ardi Abate had been working with Johnston's chameleons (T. johnstoni) as was I at the time. With the help of a reptile vet, they determined that certain levels of pre-formed vitamin A would cause gular edema (something I had experienced when feeding commercially bred crickets). As many of you know, that one article in particular led to the development of many reptile supplements that contained beta-carotene as a source of vitamin A (it was thought beta-carotene would be converted to the preformed vitamin A that chameleons need). Problem is, years later, people were finding that at least with panther chameleons, the hatch rate decreased when gravid females were not given adequate levels of pre-formed vitamin A, not to mention eye problems, etc. It seems no one really knows for sure whether any chameleons can actually convert beta-carotene or if they can, to what extent. Anyway, in the controlled study, the hatch rate of panthers went up when the gravid females were given a certain minimal dosage of pre-formed vitamin A. Of course, it is well known that other supplements (oversupplementation in general) are one cause of edema in montane species. My experiences of oversupplemtation of D3 as well as vitamin A (both of which can cause an unsightly edema, a symptom of a malfunctioning kidney or liver) has led me over the years to probably go too far the other direction in avoiding supplements like the plague. Well, one thing is for sure, I haven't had any edema problems (except from freshly, caught but dehydrated imports) whatsoever on established animals in my collection. However, as I mentioned, my last two quad clutched seemed too weak to hatch. Very frustrating. I know going full term and failing to hatch is sometimes caused by too much moisture but I don't think that's the case with these two failed hatches. My gutload doesn't include pre-formed vitamin A and if this is necessary for strong neonates, this may be what is missing.

My question is specifically for those of you that have had success hatching and most importantly, growing up quads, at least past the 3 month mark. Do your gutloads contain pre-formed vitamin A? If not, did the neonates you raised come from freshly imported females that laid? If pre-formed vitamin A is necessary (it may yet be determined that chameleons cannot convert beta carotene), then as I've read elsewhere, it is a mystery as to where wild chameleons (except those that are known to eat vertebrate prey on occassion) get their preformed vitamin A. If you do not use any pre-formed vitamin A whatsoever, it may be that your wild caught females already had an adequate level of pre-formed vitamin A in their systems that they were able to pass on to their neonates (resulting in strong hatchlings). My best "success" in raising hatchlings has been from eggs laid from freshly imported females. Analysis of various insects suggests that in some insects, the preformed vitamin A may be in the eyes of the insects themselves. This may be lacking however in the limited insect variety that is regularly available to captive chameleons.

Those of you with success raising hatchlings, please share your thoughts on pre-formed vitamin A. If I start giving some to my females, I will do so very sparingly. My guess is that beta-carotene is not enough, but I want to approach a gut-load containing pre-formed vitamin A or supplementing directly with extreme caution since I'm very familiar with the problems of overdosing with montanes.

Thanks for any help.


Retired Moderator
I will tell you this even if I get roasted for it. Once a month all my chams, even my montanes get a VERY tiny drop of vit A from a capsule. I put the dot on a feeder prior to giving it to the cham. I even did this with my quad babies and only*lost one of 9 in the last clutch, that was at the 5 month mark. Pictures of my healthy babies are posted on here quite often. Of course those people may now kill me.


Chameleon Enthusiast
You said..."in the controlled study, the hatch rate of panthers went up when the gravid females were given a certain minimal dosage of pre-formed vitamin A"...I'm sure I know the study you are referring to. Do you know if anything that was either fed to the chameleons or used as a supplement or that was fed to the insects contained D3 and what levels of prEformed vitamin A were in any of these things? I know that there has been no study done that proved that chameleons could convert beta carotene into vitamin A but this same paper talks about carotenoids in eggs...including beta carotene saying "Measurable concentrations of retinol at all stages of egg development in the chameleons suggests effective conversion from carotenoid precursors"...I would have thought that it would have said that no beta carotene was included in that conversion. I've mentioned this many times when the topic of prEformed vitamin A comes up and nobody...even the authors of the paper has commented on it....

These people bred/raised/hatched more than one generation of quads...if you could get in touch with them I'm sure they could tell you if they used prEformed vitamin A....I don't know if their email address in the "contact" list is still current...

Regarding vitamin A in insects, in all the insects that I can find information on have a form of vitamin A involved in their vision. Even nocturnal insects have vitamin A involved in their vision...and carotenoids seem to play an important part in nocturnal insects..."When carotenoids are the precursors, the insect can form....in the dark"...
http://www.ansci.wsu.edu/Courses/as464/notes/webdocs/Background Information/fatmetabolismininsects.pdf

"Periplaneta americana has two mechanisms for maintaining the level of beta-carotene in the eyes. "...
Last edited:
Thanks for the info everyone. Laurie, I've been lurking on this forum for some time and loved seeing your baby quads. What you are doing is precisely what I've been considering. A small drop of vitamin A on a feeder insect every month or so. It seems reasonable to me anyway that it would be wise to give montanes a small amount of preformed vitamin A on occassion, especially since we don't know for sure if and to what extent various species can convert beta carotene to preformed vitamin A.

I once had a female T. jacksonii that gave birth and in within days, the neonates were closing their eyes. Although I realize that many factors may have been involved (humidity, good air flow; all which was good IMO), one thing I've wondered about is what I perceived as a general overall weakness of the neonates right from the start. I'm curious about how many other chameleon breeders out there experience this, where you feel that a group of hatchlings is pretty much doomed from start (possibly due to the mother not getting proper levels of certain nutrients or vitamins; vitamin A?) I feel that many people, including myself, often have high hopes when breeding their chameleons and then hatching a clutch, but in reality, this seems to be one of the easier parts of breeding. Whether the offspring thrive and go on to produce healthy young of their own is the real challange.

Regarding oversupplentation, although both overdose of preformed vitamin A and vitamin D3 has been shown to cause kidney and liver malfuntion, resulting in edema, I believe that the majority of cases of edema I saw years ago with some chameleons in my collection were more likely due to vitamin D3 rather than vitamin A in the commercially bred cricket feeds. I once had a clutch of melleri hatch and for the first few months, I housed them outside and fed them wild collected insects. During that time, they grew great. However, as soon as the weather started getting too warm, I brought them inside and for the first time, I started feeding them commercially bred crickets. Within a week, some of them had edema (no supplementation either). Unfortunately, at the time, I did not use UVB lamps. Now, I steer clear of D3 supplements altogether and let the chameleons make their own with UVB exposure only. Again, as I mentioned earlier, over the last 5 or 6 years (since I've turned away from all powdered supplements except for pure calcium depending on the age and sex of the animal), I've only had edema issues with freshly imported, dehydratred animals. In the early 90s I had of clutch of T. johnstonii that appeared healthy from the start and was growing well. After a month or so, I fed commercially bred crickets. Within 2 days, all of the neonates had edema. Unfortunately, as with the melleri clutch I mentioned, I feel that D3 levels in the cricket mash, caused organ damage. After the edema, they failed to grow. Fortunately, I sold some of the melleri I had before I brought them inside and before I fed them commercially bred crickets. The rest of the group however, never grew normally again after the organ damage/edema. Many made it to one year of age but they were extremely stunted. No one would ever have guessed that they were a year old. Since those experiences, I stay away from D3 supplements entirely (even if housed indoors; I may feel different however if I ever decide to keep panthers or veilds). Finally, my experiences with oversupplemetation has resulted in me avoiding things that I probably shouldn't, as with pre-formed vitamin A. It's such an important vitamin that chameleons need but studies need to be done to determine which species need what amount to stay healthy and produce healthy offspring.
Top Bottom