I have started a study with the Galapagos Tortoise Alliance, collaborating with Dr Boris Tezak, to see if Dr Tezak's techniques published in his paper on "Identifying Sex of Neonate Turtles with TDSD via small Blood Samples" can be used to also identify the sex of hatchling and young Galapagos tortoises.
I have been doing studies on Temperature Dependent Sex Determination (TDSD) with Burmese Stars for a few years now. Carefully monitoring and graphing the entire temperature profile of the incubation and diapause process to later compare with sex of the young produced, once sex can be determined. This means waiting about 3 years or so until you can tell the sex of a young Burmese Star. When I saw a paper published on identifying the sex of neonate turtles -
I was immediately intrigued, and sought out the lead author to discuss application to tortoises and possible future collaboration. In addition, with the Galapagos Tortoise Alliance, our work with Galapagos tortoises and forming assurance colonies brings to the forefront the issues of creating best sex distributions of tortoises for future colonies. Since Galapagos Tortoises can normally take more than a decade to reach an age where they are reliably sexable, early determination of sex is an obvious asset! Reluctant to use any invasive techniques to sex young such as endoscopy, this use of less than a drop of blood is a very attractive possible option.
We have now agreed to start a collaborative effort to study the possible early determination of sex of these gentle giants as part of the work the Galapagos Tortoise Alliance. We will be collecting and preparing blood samples from young tortoises from newly hatched to as much as 3 years old. These samples will be sent to Dr Tezak for testing for the presence of AMH. We will be looking to see if this is indeed applicable to Galapagos, and how long that presence of AMH remains as the young tortoise ages. We will also be sending samples of blood and fluid from the inside of the eggs of newly hatched Galapagos to see if differences in protein and hormones are also detectable and useful in determining sex.
Combining the results of this study along with the study we are doing on graphing incubation temperature profiles with SensorPush, we also will be more equipped to equate the results to a better determination of the pivot point for incubating Galapagos tortoises. A most valuable tool to help incubate eggs to better fit sex ratio profiles needed for the various assurance colonies.
Exciting stuff!! And... more to come.
I have been doing studies on Temperature Dependent Sex Determination (TDSD) with Burmese Stars for a few years now. Carefully monitoring and graphing the entire temperature profile of the incubation and diapause process to later compare with sex of the young produced, once sex can be determined. This means waiting about 3 years or so until you can tell the sex of a young Burmese Star. When I saw a paper published on identifying the sex of neonate turtles -
Identifying Sex of Neonate Turtles with Temperature-dependent Sex Determination via Small Blood Samples - Scientific Reports
Temperature-dependent sex determination, present in most turtle species, is a mechanism that uses temperature to direct the sex of the embryo. The rapid increase of global temperatures highlights the need for a clear assessment of how sex ratios of organisms with TSD are affected. In turtles...
www.nature.com
I was immediately intrigued, and sought out the lead author to discuss application to tortoises and possible future collaboration. In addition, with the Galapagos Tortoise Alliance, our work with Galapagos tortoises and forming assurance colonies brings to the forefront the issues of creating best sex distributions of tortoises for future colonies. Since Galapagos Tortoises can normally take more than a decade to reach an age where they are reliably sexable, early determination of sex is an obvious asset! Reluctant to use any invasive techniques to sex young such as endoscopy, this use of less than a drop of blood is a very attractive possible option.
We have now agreed to start a collaborative effort to study the possible early determination of sex of these gentle giants as part of the work the Galapagos Tortoise Alliance. We will be collecting and preparing blood samples from young tortoises from newly hatched to as much as 3 years old. These samples will be sent to Dr Tezak for testing for the presence of AMH. We will be looking to see if this is indeed applicable to Galapagos, and how long that presence of AMH remains as the young tortoise ages. We will also be sending samples of blood and fluid from the inside of the eggs of newly hatched Galapagos to see if differences in protein and hormones are also detectable and useful in determining sex.
Combining the results of this study along with the study we are doing on graphing incubation temperature profiles with SensorPush, we also will be more equipped to equate the results to a better determination of the pivot point for incubating Galapagos tortoises. A most valuable tool to help incubate eggs to better fit sex ratio profiles needed for the various assurance colonies.
Exciting stuff!! And... more to come.