The purple firefish - Nemateleotris helfrichi - is quite popular in our hobby, and costs 2x to 3x more than a red firefish. These small fish swim in open water, twitching their little dorsal fin in the current. They are known jumpers, and fine mesh over the top of your tank is the only way to keep these fish safely. Quite shy in nature, they should get used to their tank mates in time and showcase their lavender coloration. This first picture was taken by Luiz Rocha at 80 meters (262 feet) in Pohnpei.