Cyrtodactylus incubation period variances??

Ari · #1 04-07-2006, 09:20 AM

Hi All

This has been on my mind for a while. Why is it that the incubation period with this group of geckos varies so dramatically from say 90 days to 300 days & inbetween?

Is it more to do with temperature, moisture or what that triggers them to hatch?

Like wouldnt they be fully formed at say 90 days, and yet hatch say 200 days later.

Can you see what I am getting at?

I have heard that some people have tried putting moist spagnum on the eggs to induce hatching - does anyone know if this really works at all?

Anyway all opinions sort as this is rather intriguing.

Ari

WildEyeReptiles · #2 04-07-2006, 09:37 AM

I think it has a lot to do with temperature. I've got a friend that has hatched Elok in 2 or 3 months, I forget which, but I have pubisulcus (these are smaller and one would be inclined to believe they would hatch sooner) eggs going on 6 mos that are still looking perfect, while the irianjayaensis eggs hatch around 5 mos. (IJ's being about 6x larger than pubisulcus)

I think these are a genus where diapause plays a strict role. Moisture surely plays a role, but not so much as temperature. I generally start eggs off cool and then heat them up, with other species that require a diapause, this is rather effective, so I've applied the same reasoning here. My friend kept his eggs very warm, and I think thats exactly why they hatched so much more quickly.

Bowfinger · #3 04-07-2006, 10:58 AM

Maybe some useful information? A lizard from similar habitat with temperatures affecting incubation time is the Mountain Horned Dragons (Acanthosaura). They hatch out up to 190 days with a temperature of 68-71F. You can hatch them out sooner with higher temps. but this lowers the survival ratio. Even if they hatch out they can later die before the first year, but this is not much of a factor when incubated at the cooler temperatures.

This may not be the same with the geckos but worth considering the possibility.

WildEyeReptiles · #4 04-07-2006, 12:46 PM

Quote:

Originally Posted by Phantasticus

You can hatch them out sooner with higher temps. but this lowers the survival ratio. Even if they hatch out they can later die before the first year, but this is not much of a factor when incubated at the cooler temperatures.

This is consistent with animals having a natural diapause in their incubation, and animals incubated too warm to begin with. We see this a LOT with chameleons, you can hatch them out in 1/2 the normal time, but you lose about 2x as many and they have decreased vitality.

geckodan · #5 04-07-2006, 06:30 PM

I personally don't think temperature is the only answer. I had 3 C.louisiadensis eggs (a clutch of 1 and a clutch of 2) put in the same incubation chamber on the same day. The hatching times were 90, 110 and 190 days. They were all kept in the same conditions. My gut feeling is that it is related to weather conditions. Its ok to diapause if the winter is cool because hatching has little to benefit you but if the winter is warmer, why sit around in your egg for an extra 3 months. I have also considered that it may be related to monsoon rains. Being able to diapause and then respond rapidly may be useful. Rains mean food but also mean flooding. If you are fully developed and ready to pounce then surely you have a better survival chance as a juvenile than as an egg if a flood is heading your way.
I tried the spaghnum this year with no difference. What I haven't tried is a period of cooling followed by reheating. It sounds like a fair idea so I am going home to do that today. There are turtle species in Australia that will fail to hatch if this is not done so a similar adaptation may occur in other reptile species.

Ari · #6 04-08-2006, 04:56 AM

Geckodan

Let me know how you fair with the temp drop. This is so intriguing. There has to be a reason. 90 - 300+ days thats just a massive difference.

Ari

geckodan · #7 04-08-2006, 09:08 PM

FRom memory, the 300 days was at QLD museum at room temp (recorded in Ehmann)

Ari · #8 04-09-2006, 02:53 AM

How long would you cool for & at what minimum temp Danny?

Cheers

Ari

geckodan · #9 04-09-2006, 06:41 PM

For the turtles that diapause, room temp below 22 (but preferably below 20) for 1 month.

Ari · #10 05-09-2006, 09:51 PM

I was just thinking maybe its the opposite to moisture/water causing the hatching difference, but dryness (the opposite).

Many of these species seem to be in hot/humid areas, e.g. Indonesia, Australia & Malaysia - maybe they hatch out when the temp or moisture becomes drier - surely moisture would start to dry up in the egg at sometime - particularly if the temp causes evaporation?