Blue Tang rubbing on emerald crab

[MarineReefer]

I've had my blue tang for a few months now with no issues. I got some emerald crabs n the largest 1 my tang comes next to it and beats the crab with its tail. Almost like the tangs trying to get it to move. Anyone else see this behavior or know why the tang is doing this? Ty in advance.

 

[Flippers4pups]

Not sure. They do compete for the same natural foods. Mostly algae. Same reason some blennies and tangs can't coexist.

 

[LesPoissons]

Maybe the tang is mistaking it for a cleaner shrimp? Or just going after the same algae patch if you move the crab, does the tang follow it and repeat the behavior?

 

[LesPoissons]

*I have tangs and blennies approaching 4 years, no problems

 

[MarineReefer]

Maybe the tang is mistaking it for a cleaner shrimp? Or just going after the same algae patch if you move the crab, does the tang follow it and repeat the behavior?

Yes still does it.