Sea urchin parasites? Need ID

[marv1111n]

Hello, I recently got two tuxedo urchins, and today I noticed that one of them had a small patch where spines were missing and the test was exposed. Upon closer inspection I noticed these small critters around the area. They look like amphipods but with a dark/black body and a bright stripe on their back and are around 2-3 mm in size. Does anybody know what they are and if they pose a threat to my sea urchins? And if yes, is there something I can do?

 

[Tikki]

Might try putting in a bucket of tank water and blowing with a power head maybe to see if they’ll dislodge? Can’t think of any dip offhand that would be safe.