On March 13 2012 my Red Ear Slider turtle, Gertrude, laid 7 eggs. I incubated & hatched 2 eggs two years ago & am going to try again with these. In trying to find information I couldn't really find what I wanted to know, like how to know if they're fertile, or if you can see inside them by shining a light through them etc.
Most everything I read says you can't see anything, but I disagree. With the Turtles I hatched, I saw them moving inside the eggs for weeks before hatching.
this time around I'm documenting the progress & changes of the eggs so I have it for reference & so it may be helpful to someone who stumbles upon it.
The first photo up top is of the eggs right after she laid them & I dug them up. I incubate in a plastic tub with a lid with holes punched in it & plain old dirt. Just dirt dug up from my yard or garden. Everything I read.says to use half this & half that blah blah blah....I just use dirt!
Anyhow, on day one there were no noticeable changes in the eggs. Day 2 however, several eggs had bright spots known as chalking,(see photo 2) a spot where the embryo has attached & started developing, making a calcified spot on the egg. By the end of day 3, all 7 eggs had visible signs of chalking. This is very visible when u shine a flashlight not on, but next to the egg. I believe the embryo itself to be visible in some of the photos I took. Observe photos with the light & you can see a little ring with a dot inside, I'm sure that'd the embryo itself as all eggs had it just not all photographed well..
