Many people have been given a lot of false information on the wonderfully exciting dragon goby (also called the violet goby and the dragon fish). Many are told that these fish are freshwater predators who will eat any small fish. This leads them to keep them in a freshwater tank with semi-aggressive or aggressive fish. However, this the dragon goby is both a peaceful scavenger and a brackish water fish.
It is wrong to keep him with freshwater fish. There are some freshwater fish who will tolerate brackish water conditions and it is therefore possible to keep them with the dragon goby. However, there are many freshwater fish that they can't be kept with because the freshwater fish won't tolerate long term exposure to brackish water conditions. These include angel fish, tetras, and plecos (though that list is definitely not complete).
It is also important that you avoid aggressive fish. The dragon goby is often picked on because it isn't very aggressive and often suffers from nipped fins, spines being ripped off, and constant picking on. Sometimes it is even killed by more aggressive tank mates. It is important to choose peaceful, calm fish and inverts to go with this great fish.
Getting It Right: Fish.
To get it right you need peaceful fish that can handle the same salinity as the Goby. This can be hard for those who aren't familiar with their options and for those who are struggling to figure out what is a brackish water fish verses a freshwater fish, but here are some of your options.
- Puffer fish. Puffer fish aren't always ideal they are an option. Many puffers are violent, but at the same time many do really well. Those that are less voilent will get along fine and much of the puffer aggression is toward one another. Choose dwarf puffers such as the Ceylon puffer or the figure 8 puffer. Many choose the green spot puffer, but this is a bad choice because it will eventually need full salt water conditions and your goby doesn't want that.
- Other gobies. There are a number of other gobies that make great tank mates for the dragon goby. You can choose the bumble bee goby, the clay goby, the knight goby, or the candy stripe goby. Others may work just as well, but make sure they like the salinity the same as the dragon goby and that they will be gentle with him or ignore him.
- Glassfish. There is a small schooling glassfish that is readily available. It is technically the Indian Glass Fish, but if often sold as a simple glassfish. Many times these fish are painted (dyed) and then sold as the Painted Glassfish. While they offer some appeal with lovely pinks, blues, yellows, purples, and green colors often a bit neon these fish are not naturally colored that way and natural varieties are better.
- Sharks. There are a number of "sharks" that do well with the goby. They include the Columbian shark, black finned shark, and the silver tip shark. These sharks are really catfish and won't bother your goby, however, it should be noted that some sharks need to move into more and more brackish water as they age with some needing full salt water.
- Monos or fingerfish. Some monos make great tank makes though as they get larger they may harass and stress the dragon goby, so it is something you want to be careful with.
- Mollies. Mollies are great tropical live bearers who can be placed in freshwater, brackish water, and even full on salt water (and everything in between). Contrary to popular belief the dragon goby won't eat babies if he isn't starving.
- Other live bearers. Mollies come from waters with a naturally occurring salinity. While most other live bearers don't, they can be placed in brackish water. Consider the guppy, the swordtail, and the halfbeak as possibilities for your tank.
You want to make sure that you don't over stock your tank and that you are meeting the needs of each kind of fish in your tank. You would never want to put all of these fish together (even in a huge tank) so it is a good idea to take this list and do a little research to find out the tank mates that will work best with your dragon goby and you.
Getting It Right: Invertebrates.
In addition to there being a number of fish you can add to a tank with your dragon goby there are also a number invertebrates that will do well in a brackish community.
- Snails. Most snails are intolerant of salt. However, you can keep olive nerite snails and Malaysian Trumpet Snails in the brackish water with ease. Malaysian trumpet snails will help to clean up left over foods as well as algae. Any Nerite snails you add will clean algae and other plant matter (though not live plants). A low level brackish tank (about 1.005 to 1.06 which is the low end of what your goby needs) can also house Columbian Ramshorn snails and some nerite snails including the polka dot, orange track, African zebra, Tiger, Ruby, and the Indo-Pacific zebra. The Clithon corona or spiked nerite can be kept in salinities up to 1.01 and some other species can be kept in salinities about 1.01 (to 1.025) including the Virgina Nerite, the American Zebra, and the Chameleon.
- Shrimp. There are three options for the shrimp that you choose for your tank. Some report the dragon goby eating small shrimp, but others have had success keeping Ghost shrimp and the dragon goby side by side. The truth of the matter is that your goby will snack on a shrimp if he is hungry enough. You should make sure that he is well fed before adding shrimp. The ghost shrimp will do very well in any salinity. Two other shrimps that do well in the same brackish water as the dragon goby are the red nosed shrimp (sometimes called the Rudolf shrimp) and the amono shrimp.
- Crabs. Freshwater crabs are really brackish water crabs, but can only be kept if they have a land source. This can work in some set ups, but is often a pain to do with your goby. Remember you goby wants a lot of room to move around and will get large (usually about 18"). The brackish water crabs are partially terrestrial and really want a good space on land with sand to dig in. This makes them a bad choice. If you are choosing a high brackish tank however, you can keep blue legged hermit crabs in there. The salinity must be 1.01 or higher to do so and you will want to provide them with plenty of shells to choose from as they grow.
It should be noted that when you are choosing inverts for your tank you want to make sure that you are picking creatures that will do well in the salinity of your tank. The dragon goby likes water from a 1.005 to 1.012. This gives you a large range and you can choose to have a low, mid, or high salinity brackish tank.
While goby fish can't be described as community fishes (because they live in salt water and don't mix with those other fish typically seen as community fish) they can make a great focus fish for a great tank. You will find that you can have a well rounded and beautiful brackish water fish tank!