Hey! So I've been breeding Guppy for about 5-6 years and I've somehow escaped any sicknesses in my aquariums. I recently bought a new guppy. My question: Her belly is VERY sunken, it's like a Straight line from her head to back tail fin. Also, she started hitting herself on tank decor. Water parameters are all in safe zone. Checked them today. What do you guys think it could be?? Any treatment? Thank you! P.S. I'm going to my LFS today so if you recommend a product I'll be able to buy it today.