Mandarin gobies are some of the most unique fish you could ask for. The Blue mandarin comes in a variety of colors such as red, orange, blue and purple. They are most happy with a 30 gallon or larger aquarium with live sand and plenty of hiding places. They are a great addition for a reef tank and also do well with seahorses! Their diet should consist of a variety of both frozen and live brine shrimp and live black worms.