Dots or 'pimples' on motoro?

[MnKoi]

My small, about 8" disc female motoro (new to me) has some small dots or pimple like bumps on the top portion of her disc. She is active, eating healthy and is usually cruising around the tank. I have her in a 90 gallon (I know, it's temporary) with a coarse sand substrate. Filtration is an AC40, Emperor 400 HOB and a JBJ canister filter. I'm doing daily water changes as the filtration is nearly matrue, just showing a touch of nitrItes right now. I've kept fish for years, but am new to rays. I have read a lot on this forum as well as other literature but I can't seem to find information about these bumps. Anyone have any ideas?

 

[PeteLockwood]

Look up denticles.

1 Teaspoon of salt will help her with the nitrIte. Replace appropriate amount of salt as you change water - so if you change 50% replace 1/2 teaspoon. Yes, just a teaspoon. Any salt, table salt is fine.

 

[hereticlosmorte]

it almost reminds me of goose bumps that we humans get.
alot of stingrays develop denticles, more so when in hard water environments. it's no cause for alarm.

 

[MnKoi]

Very interesting. I appreciate the replies!