Coralline and Crabs

[normanknight]

Hi all
I have some live rock with beautiful coralline growing on it. I just added two blue leg hermit crabs. They are quite small, but I have noticed that where they crawl on the rocks, the coralline is vanishing. I thought they ate mostly green algae. Can I expect them to completely remove all my nice red coralline? I will brace myself for your replies.

 

[tizzo]

What kind of hermits? I never heard of hermits eating coralline.

 

[rollagore]

I have a lot of hermits some of the are blue leg and i have no prob with my coralline. I have never heard of hermits eating coralline. I could be wrong but i would look for somthing else unless you have seen them eating it with your own eyes.

 

[normanknight]

OK
The crabs are Marshall Island Electric Blue Hermits (calcinus elegans). Wherever they crawl on the rocks, the coralline vanishes and the rock turns white or back to its original color. I never ran into this before the crabs were introduced. I don't have any fish that would do this. The only fish in the tank are a firefish goby, a diamond goby and a clown. I also have a coral banded shrimp, that stays hidden most of the day, and a cleaner shrimp.