Urchin and Coralane algae

[Chip]

Dr. Ron: I forgot to ask you this in my last thread. I have three sea urchins. One is black with needle thin spines, one is greenish brown with shorter and fatter spines, and one is pink with short very hard spines. The pink urchin moves around alot and eats the coraline algae on my live rock. My coralane algae is very dark purple but where the urchin eats it there is only whitish blue spots left.

1. Is this harmful to the coralane and will it grow back.
2. Are the whitish blue spots coralane or is this where it has been completely removed.

Thanks Chip

[rshimek]

Originally posted by Chip

Hi Chip,

1. Is this harmful to the coralane and will it grow back.

Yes, and yes. It is eating the coralline. Generally the coralline will grow back.

2. Are the whitish blue spots coralane or is this where it has been completely removed.

Probably completely removed.

See my article on urchins in the November, 2003, issue of [rk].

:D