Cowries?

I've got two. One is my in 45 and I have this giant one in my nano. Seriously this guy is like three inches across. HUGE.

Mine are voracious algae eaters. Both of mine do an awesome job on hair algae. I love the look of them and they can turn themselves over if they fall so that's a plus. Just be careful as not all cowries are reef safe. Make sure you get the type that won't munch corals.

I've had this bloom for about the last month. Here is a link to pictures of the tank, everything is for sale but just in case it doesnt sell I would like help on getting the algae under control, thanks Mark

Hawaii 
But I seem to remember something about them being coral predators. I'd check on that before buying.

I'm wondering if we are again falling victim to the problems of hobbyists that don't provide enough of the right environment for some specific animals - they turn to eating coral.  We may also propagating the myths, myself included.

Found this interesting statement below, posted on RC after someone had posted that the only Cowrie that won't eat coral is the Money Cowrie. Personally, I would only have a cowrie in a well established tank that has had at least a year to grow sponge and other algae-bacterial biofilm which appears to be their main food.

"...most cowries are NOT known for eating corals. [Their relatives,] ovulids feed on one "soft coral" or another, and since they look like cowries, and the people who are considered to be reef experts (they aren't mollusc experts for sure) call them cowries, this myth gets propogated throughout the hobby over and over. It doesn't help that at least one of the authors published this as a fact, and then illustrated it by showing a pic of an ovulid, not a cowry, feeding on a leather coral. Dr. Burgess, who published a guide to collecting and identifying cowries called "The Living Cowries," noted specifically that it was a waste of time to look for cowries among live corals, because they don't feed on live corals. They are found under dead coral slabs usually with sponge growth and microscopic animals to feed on, along with various sparse algae growth. I've found this to be the case also. There are only a few small species of cowries that may be found in association with live corals, and none of them have been observed to be feeding on them, although it's possible. These include Cypraea poraria, Cypraea fimbriata, Cypraea irrorata, Cypraea minoridens, and Cypraea microdon. None of these has ever shown up on any of the reef tank forums, as far as I'm aware, and none of the suppliers sell them to hobbyists. As I've stated several times before, large starving cowries in small tanks may start tasting of things, including potentially corals, which isn't exactly the same as saying all cowries feed on corals, since none of them are known to do so."

The pic below is what I believe to be a Cowrie (could be an ovulid) that Adam brought back from Hawaii many years ago. It lived in this well established 180 for at least 4 years. It's midnight gray colored mantle usually covered the entire shell making it almost invisible in the dark areas of the tank where it spent most of it's time. The mantle was like a brush with thick 1/2 inch long protrusions, giving this animal a fascinating look.




Edited by Mark Peterson - November 26 2010 at 12:23pm