Could you please explain about egg axis in marine turtle? How to position the egg in order not to change the axis when one have to move it to the artificial breeding ground? Can we see the axis from external morphology of the egg? Cheers.
The egg axis is as per the NS pole of the Earth following the angle of dip
Thank you prof. Mitra. What should be doing if we will have to move newly laid egg to an artificial breeding ground? how to keep that axis to ensure survival in hatching. Could you recommend some readings please? I tried to download some of your publication in RG without success, only the cover can be download.
Why not make a little marker on the top side of the Egg bevor moving ?
Make the mark at the top of the egg with a pencil or another non-toxic marker. Transfer the eggs onto a tray filled with damp sand. Place each egg in a depression you make in the sand with your thumb or finger so that the egg does not roll while being transported.
To add just a little more to A. R. Breisch' excellent suggestions, you could have the one mark you make satisfy two aspects: it could be on the top (showing which side was originally "up") and could be just a small arrow showing the original due north bearing. You could also consider adding a number representing the layer of the egg when found in a clutch (1 for the top layer, 2 for the second one down, etc.).
Hi Norma, there are some methods to move the freshly laid eggs. The practice depends on how far will you travel and facilities at the nesting beach. Last year we moved four clutches of freshly laid eggs (app. 10 hours traveling distance) by first chilled them to app. 10-15 degree Celsius for eight hours to retard embryonic development. its proven a safe practice as we got almost 90% hatch success under laboratory incubation then.
Alternatively, you can create a hypoxia condition in extending embryonic arrest in order to avoid movement-induced mortality. But this is pretty recent method by Richard Reina research group. Personally I haven't tried before.
Btw, how far are you moving the clutches and at what stage of incubation?
Thank you Rusli, I am sorry for this delayed reply. They were moved as soon as they are found, to a distance not more than 3 km normally.
Then I reckon it should be no problem at all as it won't take more than a couple hours I guess. What is your current research interest related with sea turtle?
Thanks. My query is how to confirm egg axis in turtles. To my believe, as turtle is dorso-ventrally flattened, once the egg axis 'twisted' during transportation followed by placement even in a 'slightly different position' in their artificial den, it may retard the embryonic backbone during subsequent development. So, I wonder how to accurately establish egg axis in its original position after thrown out of the cloaca.
To my knowledge, embryo development haven't started yet within this early period, thus the egg axis hasn't established yet.
Does it mean that one could simply take the egg and roll it randomly into a new den? I doubt it. Do you have pictorial embryology of turtle egg I could ask please? Thank you for the sharing and the discussion with me.
No worries. Its a good question though. You may contact David Booth at [email protected], or Richard Reina at [email protected]. Both actively working on the embryology of sea turtles.
Btw, if you managed to find different perspective than mine, feel free to share it here.
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