This website has all sorts of x-ray pictures of an array of animals... including fish and rays! Above is an incredible x-ray of an unnamed ray, highlighting the skeletal structures. You can see the muscle striations as well.
X-rays of animals aren't a new concept. Plenty of animals have had to get x-rays, yet not many people are allowed to see such amazing pictures.
This ray was identified as a freshwater species, Heliotrygon gomesi, discovered in 2011 in the Amazon Rainforest. Besides the looking like flattened pancakes (and they've got the color to match those perfectly browned ones at iHop), these rays get big, and have slits on their bellies that you can almost see on the x-ray.
Even if you don't know the anatomy of the animals you are seeing, these are a fantastic example of how art and science can come together. Plus, look at those gills and little anal fins!
So, enjoy the beauty that is inside all of us!