When I bought some Hawaiian Volcano shrimp from J&L last month, I read that they feed on cyanobacteria. As a test (since I don't always trust what I read online
), I took some small pieces of live rock with cyano and even turkey basted cyano into their 5 gallon tank. Sure enough, there's no sign of cyano anywhere in there. They just slurped it up. This is the link to the source of this original info:
http://www.aquabotanic.com/?p=723
Unfortunately, if you have fish in the tank, the Volcano shrimp will become expensive snacks much quicker than they will be able to perform their cyano biological control
Looking again at your pics, it does look fish free.
If I come to the Victoria swap meet at the end of the month, I can pop into J&L and grab a few Volcano shrimp for you if you want and if they are still in stock.