Now for something a lot smaller. Brachygobius (Bumblebee gobies) are suitable for those of you who cannot keep a large brackish water aquarium, because they will be quite happy in a 60 x 30 x 30 cm (24 x 12 x 12 in) tank. Although these fishes are small, we do not recommend using anything smaller than this because it is more difficult to maintain good water conditions in a small body of water.
Retail outlets tend to stock only a few brackish water fishes because people usually want either marines because of their flamboyant colours or freshwater as they are easiest. The main brackish water fishes available are Scats, Monos, Archers, Arius catfishes, Mudskippers, Anableps, and Brachygobius, plus, if you want to see them at their best, Sailfin mollies (Poecilia sp.). This last group has been dealt with in the Cyprinodonts chapter.
Some of you may be tempted to keep Cyprinus carpio (Koi Carp) in an aquarium and we would like to advise against this. Koi are potentially large fishes best housed in large purpose-built ponds with powerful filtration systems.