Well first off, it wouldn't be a bad idea to remove the suspect Brittle Star, though I would guess a <50% chance that it was the culprit.
There are several aspects to note.
1- Some shrimp sold as Peppermint are not and don't do much for Aiptasia. At certain seasons the most reliable Aiptasia eating P.Shrimp are available from Florida.
2- If the P.Shrimp is not hungry and the owner feeds too well, the P.Shrimp will not touch the Aiptasia. The most reliable way of getting P.Shrimp to like and go after Aiptasia is to first place the shrimp in a tank where Aiptasia are the only food available. MSM in Centerville keeps theirs in a separate tank where rocks with Aiptasia are periodically offered. You can do the same in a bucket for a day with a rock of Aiptasia. Definitely feed the tank well prior to adding the P.Shrimp and starve it for a few days after.
3 All Shrimp are especially susceptible to improper acclimation procedures. FYI, acclimation is not for temperature, it's mainly for adjusting them to salinity and pH and their exoskeleton creates a need for extra special care both in physical handling and acclimation. For some reason they are more sensitive than another familiar organism with an exoskeleton, the crab. Shrimp are best acclimated slowly in an opaque container. Take at least 30 minutes to change 1/2-3/4 of the water in the waiting container before adding them to the tank, but do not leave them in the container for more than ~45 minutes. Drip acclimation is not necessary. Slow transfer of water a half cup at a time works well. Do not float them in a bag in the tank. They are hiders. Floating in open water is extremely stressful to them. When ready, set their waiting container slowly down into the water letting it fill slowly and move the container near the rocks so the Shrimp can quickly run over to the rock in the protection of the container without having to swim through open water.
4- Shrimp are very prone to heart attack. The stress which causes heart attack can be brought on just by being alone. It can also be caused by moving to a place where they do not know the hiding places. Introducing them to the tank in the dark or moonlight has definite advantages. I suggest buying three, even if you only need one. The chances are one will die, which leaves you with two and they really do best in groups, though one surviving Shrimp can live a long time in a Nano. I would definitely consider keeping at least two P.Shrimp per 50 gallons and that means buying three or four. (FYI, I suggest the same for Clownfish who also seem to have a similar mortality rate.)
5- Ideal living conditions are slightly different for shrimp than for fish. Shrimp are, after all, invertebrates. This means they are more susceptible to N compounds. Additionally, their exoskeleton creates unique needs and problems, like the need for protection after molting and the need for proper Alk, Ca, Mg, Strontium and other trace elements in the water to provide the abundance of minerals to grow new exoskeleton every 2-6 months.
I'm sure there is more, but that's all that would come out of my head this late at night.
As an interesting side note, Peppermint shrimp are in a group of animals that are simultaneous hermaphrodites, meaning that they can be male on one day and female on the other. The details are in an article in an old WMAS Sea Star Newsletter. Here is the link to that newsletter: http://www.utahreefs.com/SeaStar/wmasSeaStarOc00.pdf - http://www.utahreefs.com/SeaStar/wmasSeaStarOc00.pdf
Enjoy and good night.
------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|