I am in my iPhone, but yes that looks like the fertilized "spot". Candle it in a week and then you should see all the veins inthe egg. Pretty cool. Candle it in another week and you will see the embryo moving.
I just set Swordtail's timer for his bath and paused it so I could actually fill his soaking bowl up and he crawled over my phone and canceled the timer
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!