Cooler water? I'd guess around 8 gallons maybe?
I think it would be kinda weird to see this kinda ammonia damage in such a small ray when I've transported so many much larger rays in the past and never had any kind of issues, some even traveling further/longer, sometimes without even having water changes.
I moved some sand. She swam right over to the pile and flopped in it. lol She appears fine from the top. She is supposed to be quite fond of swimming on the sides I guess, maybe it's possible these are from the cooler?
I fashioned up a divider just to be sure the fish don't bother her.
I tried shrimp and she didn't budge, but she couldn't resist the crawlers, so hopefully it's nothing super serious.
2 years old and looks to be 6-7" across....