Amaya Xylina - the Japanese Medaka Miracle

In the perspective of Amaya Xylina herself.
As told to Kaylyn Means and Sue Ann Smith.

This was what I looked like when Kaylyn and Sue first saw me.

I was 13 hours old. Below, Kaylyn and Sue labeled me. In this stage (stage 13), the dorsal lip gastrula of blastopore was visible along with the boundary of blastoderm. About 1/5 of the surface of the yolk's sphere is covered. The germ ring and embryonic shield are not visible yet.



This is what I looked like the second day. I was in stage 19. Below, Kaylyn and Sue labeled me. Two divisions of the brain are visible. The closure of the blastopore is complete and gastrulation (the formation of germ layers) ceases.


This is what I looked like on the third day. I was in stage 21. The tail bud is formed. The gut has developed in the trunk region. The optic cups are formed without the lenses. Three primary brain divisions are visible.

This is what I looked like the fourth day. At this point, I had a heartbeat! It was 84 beats per minute. There was no circulation yet, and my optic lenses fill my optic cups. My head and my tail have started to lift off the yolk sac.


This is what I looked like after the 3 day weekend! (The fifth day) I had a major increase in heart rate now at 120 beats per minute! I was also a lot more visible without the microscope. Sue and Kaylyn think I could hatch any day now!! I am in stage 26. I now have circulation - clear blood containing a few cells
This is what I looked like the sixth day. My heartbeat was 125. I was in stage 28. My blood was pink. It was most obvious in my heart. My tail got longer. I now have 30 somites which is fully developed.

This is what I looked like the seventh day...I had a constant heartbeat, and Kaylyn and Sue can see my pink blood pumping through my body! I now twitch in my tail. My cornea is visible and still is touching the optic lens. My heart appears doubled in size because all heart chambers are differentiated.

This is me after I face... My eyes (the black spots) are visible, and you can see my fin (to the right).
[[image:Amaya_6:2:081.jpg]] tail...

Sue and Kaylyn learned that the natural breeding season for the Japanese Medaka is from mid-April to late September to maybe even August. Light has a great influence in when the mating starts and when ovulation occurs. Once detached from the female, eggs could be eaten by adult fish and snails. Also, you can't use tap water, instead it must be spring water. Once your fish gets sick, there is no dependable cure for the disease that your fish has.

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