Urchin and crabs

[JJIM]

Will crabs such as the emerald, blue leg, and scalret red hermits kill Royal Urchins, or are Urchins left alone by these small crabs?

 

[finsurgeon]

Left alone...haven't seen any of my crabs touch any of my urchins over a 4-5 year span, and have had blue tuxedo with all of the above crabs, among others, the whole time.