Lettuce Nudibranchs for algae

[AxelG]

I've got a pretty bad case of green algae on my rocks and I was wondering if lettuce nudibranchs would help out? Would they end up becoming expensive food for one of my crabs? In Roland's post on Trocus Snails a couple of people talked fairly positively about lettuce nudibranchs. Any dissenting opinions out there?

[horge]

Hi Axel,

Lettuce sacoglossans (not "nudibranchs"; and Tridachia crispata has been properly re-designated Elysia crispata ) are losta fun.

As molluscs, yes, they can be viewed by crabs and large fish as potential food, but they can and do store the defensive chemicals of the algae and seagrasses they graze on, to make THEMSELVES taste very bad to most would-be predators.

E. crispata is a fairly good herbivore, but more of a lagoonal, inshore critter than one from the reef proper (so to speak).

hth
horge

[Rhoad Kyll]

I have 4 of them in my tank and they graze constantly on algae. They work great. I will probably get 4 more to keep the stuff down.