Reptile Forum, Reptile Classifieds - CaptiveBred

[Rickeezee]

Please would anyone who has hatched Yemen eggs tell me:

What incubation temperature they have found to give the best results:

Was the temperature used constant day and night:

if not constant what the differential was, to include day temp and night temp:

Has anyone found different temperatures yield gender bias e.g. more males at a certain temp, more females at a certain temp:

Has anyone found that the egg spacing in the incubator has made any difference e.g. close together all mainly hatching at the same time, or further apart hatching rate over a longer period of time.

Length of time from incubation to hatching as applied to the above experiences / scenarios:


Soz to ask so many questions but as the saying goes if you don't ask,,,,

I really would be interested in peoples experiences please, whether they be successful or unsuccessful. Thanks
Rick
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[Rickeezee]

Soz forgot to say on my previous post. There are no right or wrong answers, I am interested in peoples experiences, and not always when things work out well, although it is nice to hear when they do, but also when things don't go so well as these experiences are the ones IMHO that we learn the most from.
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[Scott W]

Some great questions there Rick.

So far I have found fertile yemen eggs to hatch at almost any sensible temperature, from room temp to standard incubator temp. Also not found that there was much of a delay between hatching at different temps.


The eggs being close together would make an interesting experiment, something I haven't had time for yet.

The only time I have lost bigger %'s of eggs is when I have not dug them out of the nesting box within a day of being laid.

Hopefully other people might have some more data to add to this thread....I'm afraid I'm not one for keeping good records of incubation times & temps (never enough time).
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[Rickeezee]

Thank you Scott. That info is helpful. I have heard from other people on quite a few occasions that they have lost eggs due to not getting them out quick enough when deposited. Not just with Chameleons.

I look forward to reading other peoples experiences.


Rick
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[Peter Parrot]

[Rickeezee]

I should also have added in my first post. People will be familiar with the theory of diff temps diff gender ratios.

The egg spacing theory suggests; that if placed close together the eggs will chemically communicate and hatch at the same time. The weaker eggs will hatch too soon thus leading to inferior babies with potential problems later on in life.

The theory suggests that if placed further apart, the hatch rate differs, hatching takes place over a prolonged more sporadic period, leading to healthier babies. The theory suggests in this case the eggs hatch when ready to do so. If anyone is interested I can dig up more details as an experiment has been conducted on this already.
Rick
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[Peter Parrot]

Rick this isn`t my findings , it`s taken straight from a book but you may find it interesting

In one experiment, clutches of C.c.calyptratus eggs were split into three groups. Group 1 was incubated at a temperature ranging from 80 to 88f during the day with a temperature drop reaching a low of 74f in the evenings. Group 2 was incubated at a constant 82f, and Group 3 was incubated at a constant 92f. All three groups of eggs were placed close together in 1.5 parts perlite mixed with 1 part water (by weight) in seperate one-pint delicatessen cups. Group 1 (the eggs with the nightly temperature drop) hatched first, Group 2 hatched second, and Group 3 hatched last.
Unlike some species whose eggs may hatch over several days, C.calyptratus hatchlings emerge from their eggs all at the same time. It is thought that this mass hatching may be a strategy designed to increase the hatchling survival rate by presenting would-be predators with many moving targets at once. If, in the wild, C.calyptratus eggs are buried deep in the ground, mass hatching may allow hatchlings to help each other dig their way to the surface. This remains to be determined. Interestingly, in captivity, eggs from the same clutch that are split and incubated in seperate containers hatch simultaneously within a given container, but each container hatches independantly of the other. This suggests that there is some sort of communication process going on among the eggs that forces them all to hatch simultaneously. In an experiment conducted by Petr Necas in Czechoslovakia (one of the first to hatch C.calyptratus in captivity), a clutch of C.c.calyptratus eggs was split into two groups and incubated in seperate containers. The first group was incubated with eggs placed close together. The second group wasincubated under the same conditions except the eggs were placed apart from one another. Eggs that were incubated together had only a 79 percent hatch rate and hatched all at once. Some of the hatchlings were smaller, ranging from 2.1 to 3.0 inches in length (from nose to tail tip). Eggs that were incubated apart hatched over a 27-day period, but had a 95 percent hatch rate, with hatchling size ranging from 2.6 to 3.0 inches in length. Two of the hatchlings from eggs incubated together died within the first month, whereas none none of the hatchlings died from the eggs that were incubated seperately. This suggests that the first eggs to hatch chemically signal the rest of the clutch to hatch as well. As a result, other eggs that would otherwise not be ready to hatch are forced to hatch as prematurely. (The C.I.N. calls this phenomenon a mass hatching response.) The hatchlings that are incubated together are normally smaller and weaker. This is evidenced by the observation that the difference between the largest and the smallest animals hatched from eggs incubated together is almost 0.9 inch (2.3cm), while the difference between the largest and the smallest animals hatched from eggs incubated apart was only 0.4 in.(1.0cm).
Another experiment by Petr Necas showed that eggs subjected to daily ambient daylight had only a 37 percent hatch rate, were on average an inch smaller, and hatched 15 to 17 days earlier then other eggs (from the same clutch), that were incubated in total darkness and had an 81 percent hatch rate. These findings suggest that daylight during incubation and the mass hatching response coth cause C.c.calyptratus eggs to hatch prematurely (Necas, 1991). Hance, it is recommended that C.caiyptratus eggs be placed no less than an inch apart from each other in the incubation medium and incubated in total darkness. Again, incubation at 80 to 88f during the day with a 10-to-18f temperature drop in the evenings has been used successfully; however, a cooler daytime incubation temperature may give better results. Further field measurements from the C.calyptratus habitat are needed to confirm the correct incubation regime.



Hope this helps mate
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[Rickeezee]

yes it does help, thank you for taking the time to find out the info for me, much appreciated, cheers.

Rick
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