A yellow tang. 'Bubbles' - from the film 'Finding Nemo' - is a yellow tang (Zebrasoma flavescens) who is obsessed with the bubbles that come out of a treasure chest in his tank. Bubbles or 'airlines' are very important in fish tanks, as they aerate the water. If you were to leave some fish in a tank with no airline, eventually they will use up all the oxygen in the water and they could die. So it’s very important to have an airline in your tank. If you keep fish and you see them coming to the surface and gulping, they’re not looking for food, they need oxygen. Gulping the air is not good for them, so make sure the tank is aerated. The bubbles also help to push the water around and stop the water becoming stagnant. The yellow tang is also a surgeonfish like its family-member the regal tang, who you might know as 'Dory'! Unlike Dory though, these yellow tangs can be kept in groups and they won’t fight. In the wild they can be seen in groups or solitary in coral lagoons. Here at the Aquarium, we like keeping these fish because they feed on stringy looking hair-like algae, which to us aquarists looks very messy. So the fish do a good job for us with this algae. The tangs pick at the algae to stop it forming a mass of algae mess, they will pick it off from rocks and the base of corals. Also, if a turtle happens to pass by (not in our tanks as we don’t have turtles, but in the wild) and has algae growing from its shell, the yellow tang will give it a cleaning service, eating the algae away from the shell and cleaning the turtle up nicely! They are a solid bright yellow colour in the daylight, though during the night-time the colour fades. A visible brown patch in the middle can be seen, as well as a white band going vertically across. When morning comes, they revert back to bright yellow. We have our lights on timers, they come on in the morning and go off around 6.30pm, so unfortunately visitors won’t be able to see this change. It’s important to have a day and night cycle with fish and all animals - like humans, they need to know when it's bed time!