I was trying to find it on the internet for you, but I don't know what P is? What's the genus for your girl? Also, keep in mind when I find you the information the natural expectancy will be longer than captive expectancy for the most part. She was a pretty big girl, although I'm not sure what the maximum size for your ray is.
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Phishie

"An ounce of prevention is worth a pound of cure."