So as I posted the other day, I did a bad thing and brought home another betta cup rescue. I have noticed this light spot at the base of his tail right where it splits in two since he was in the cup, and assumed it to be part of his coloring. After a few days he's been out and about more and I've gotten a better look at it, and... I'm just paranoid. I'm pretty sure I can see light shine through the spot as he swims. It doesn't appear to be an actual wound or disturbance in the skin, but it's definitely thinner than the rest of the flesh, and when the light shines through the right way it looks pinkish. I'm afraid it may be something of concern and I just don't want to wait to ask. He seems very healthy, eats well, swims well, it just looks really strange and I've never seen anything like it. Is this maybe just a thing with double tails? Betta experts weigh in please? I just spent an hour trying to take a photo that even shows it, and this is the best I could do. I'll take a video if necessary.