There are some salt water fish that are often sold in pet stores that you should avoid. These fish have a very slim chance of living in your captive tank. One of these types fish is sold very cheap (usually around $10-$15 each ) and have about a 97 to 98% mortality rate after a month or so from being out of the Ocean. They are also often sold to help rid your system of the parasite ich. This fish is the Cleaner Wrasse. Please don't buy these fish, ever! They are the oceans parasite removers for many other fish and don't stand a chance in your tank. It's best to leave them be in the ocean where they belong.