Dragonfish aka Dragon Goby Caresheet

Dragon Goby Care and Pet-Keeping Information Care Sheet

Dragon Goby Dragonfish Violet Gobies

About the Dragon Goby:

The Dragon Goby, also sometimes called a Dragon Fish, or a Violet Goby (scientific name Gobioides broussonnetii), is an oddball brackish water fish that can make the most interesting pet provided that you care for it correctly.  I can NOT emphasize this enough – Dragon Gobies are BRACKISH water fish.   Aquarium  Salt, such as Jungle Labs Aquarium Salt does NOT make brackish water.   Brackish water is found in nature where the sea meets freshwater and the two mix.  You absolutely, positively MUST use SEA SALT also known as MARINE SALT made for aquariums (no you can’t use sea salt you find in the spice aisle of the grocery store.)   Aquarium salt does not brackish water make.  To illustrate:

You need Marine Sea Salt to make Brackish Water

You need Marine Sea Salt to make Brackish Water, Not Aquarium Salt!

I have actually heard pet store owners tell me the exact opposite, and my theory on this is that either the pet shop owners do not know that Dragon Gobies need marine salt, or they do know and simply can’t make a brackish water tank in their store, or they do know and don’t tell potential owners, so when their Dragon Fish slowly gets sick and dies a few months later, they will of course get more sales.  Healthy, properly kept fish do not make for good sales in the fish business unfortunately.

References:  Yahoo Answers  |   All Experts

Generally 1 cup per 5 gallons makes brackish water. depending upon you “cup size” the SG ranges from 1.010-1.015 any of which is acceptable for brackish fish. salt generally dissolves within 15 mins, with plenty of circulation.

The Violet goby has a long, slender, eel-like body. Its dorsal and anal fins run almost the entire length of the body. The teeth are very sharp; however these are used for scraping algae off rocks, not fighting. When kept in good condition, dragon gobies develop an attractive, iridescent, silvery-blue metallic color with a gold blotch pattern.

They have large mouths with very small teeth used for scraping algae from stones, as well as large gills for filtering out sand. Their modified ventral fins allow them to cling to the walls of aquariums.

They are very shy, timid creatures which are not-aggressive and should not be housed with aggressive fish that may hurt your Dragon Goby.  They also have extremely poor eyesight and are nearly blind. The violet goby is only kept with peaceful fish, as it has poor eyesight and may be bullied by more boisterous fish.  However, if two violet gobies exist in a tank too small, one will eventually claim the entire area their own territory and fiercely defend it, even from the other dragon goby.

The Dragon Goby is Native to:

The Dragon Goby is native to Florida as well as along the Atlantic coast from Georgia in the United States of America, down to northern Brazil and other parts of Central America.  Violet gobies usually inhabit brackish swamps, streams, and estuaries with a muddy substrate. (See more under substrate).  They live in places where ocean water meets freshwater streams and rivers, so properly mixed brackish water should be between the salinity of sea salt and that of freshwater.  Ideal brackish water salinity ranges from generally 1.010-1.015 any of which is acceptable for brackish fish. Marine salt generally dissolves within 15 mins, with plenty of circulation, at which time you can add it to your tank.

Dragon Goby Average Lifespan:

A Dragon Goby can live to be up to 10 years old in captivity.  In the wild they have been known to live for up to 15 years but 10 years is the average for a Violet/Dragon Goby kept in an aquarium.

Dragon Goby Average Size:

These fish are monstrous.  The cute little ones you purchase at the fish store usually are between 6-10 inches in length, which are babies.  Dragonfish get to be absolutely huge, usually 1-2 feet in length and very bulky.   While they get larger in the wild than they do in captivity, they still can get to be absolutely huge!   This break-taking video of 2 Dragon Gobies purchased at Wal-Mart (which by the way, I NEVER recommend purchasing fish from any Wal-Mart, anywhere, for any reason, and she has these particular Dragon Gobies in FAR too small of a tank) that are absolutely immense:

Dragon Goby Enclosure and Housing:

When purchased as babies, these can live for a short while in a brackish water aquarium that is 20 or 30 gallons but will soon need to be moved to a 55 gallon if not a 125 if yours get larger than normal!   As you can see from the above video (the lady in the video had those in far too small of a tank, those Dragonfish needed at LEAST a 125-300 gallon tank), they will need room quickly as they grow, so it is best to start them off in a large tank such as a 55 gallon.

In their aquarium, it is vital to have hiding places for these creatures – Dragon Gobies are incredibly timid and shy.   My own dragon goby lives in an aquarium with Greek columns on the bottom supporting a Colosseum on the top which comes partially out of the water for my red crabs.  This is an ideal set-up as my Dragon Goby loves to swim around the pillars searching out food, then glides back up into his “cave”, the inside of the Colosseum.  If you want to see your Dragon Goby more often, place a flat rock or large clam shell seashell against the glass, and he will think it is a cave and “hide” right up next to the glass between the glass and the rock or seashell.

Dragon Gobies have extremely poor eyesight and are easily frightened because they can not see very clearly at all, so take that into consideration when constructing your hideouts for him.  Be sure the aquarium has at least one cave your Dragon Goby can go into to hide which is appropriate for his size so that he can’t get stuck.

Dragon Goby Substrate:

One thing many people do not know about Dragon Gobies is that they absolutely require a sand substrate in their aquarium.   Dragonfish are filter feeders, the way that they feed is by sifting through sand on the bottom of the aquarium (or through mud and sand in the wild) and eating the food while discarding the sand.  You might see your Dragon Goby “gulping” or opening his mouth wide repeatedly on the bottom, that is partially how they eat and is just one method they filter water and sand for food.

Be sure and get aquarium sand which you can usually purchase at your local pet shop, or online (click here to see a selection from PetSmart.com) and not gravel as they need sand to be able to eat naturally.  Their key method of obtaining food is by scooping up mouthfuls of sand and sorting edible material from the substrate, and then spitting out the substrate and swallowing the food particles.  They have large mouths with very small teeth used for scraping algae from stones, as well as large gills for filtering out sand.

Dragon Goby Heating and Temperature Requirements:   

Violet gobies are generally healthy at temperatures between 77-82°F (24-26°C), ideally at right around 80 degrees, so you must keep a heater in your aquarium for your Dragon Goby.

Dragon Goby Feeding and Water Conditions:

As mentioned above, Dragonfish are filter feeders, meaning that they sift through sand on the bottom of the aquarium, eating the food particles and spitting out the sand.   They can also use their teeth to scrape algae from rocks and aquarium decorations.   There are a variety of foods you can feed your Dragon Goby.  Remember they are scavengers and are also very lazy filter feeders.  Some ideal foods are shrimp pellets, algae wafers, bloodworms, brine shrimp and sometimes flake food and occasionally guppy fry.  Algae is a main part of their diet, but a varied diet is the best!

The water must be brackish which is about 1 cup of marine sea salt to 5 gallons of water treated with a de-chlorinator and water conditioner.  Even though you are adding marine salt, you still must remove the chlorine and other toxic chemicals in the water first by using a water conditioner such as Aquasafe.

Dragon Gobies need very clean water so you should perform frequent partial water changes, and have good filtration and waterflow set up in your tank.  Dragon gobies are also quite sensitive to ammonia and will gasp at the surface of the water if suffering ammonia poisoning.

Dragon Goby Behavior and Temperament:

Even though these fish look intimidating, and some ignorant pet shop owners even profess them to be aggressive, these are actually very shy, timid and un-aggressive fish.   They love to hide in dark tight places, and must be kept with peaceful tankmates.  They tend to come out in the dark, or in dim lighting.

Good tankmates for a Dragon Goby are other peaceful brackish water fish and creatures such as guppies (the Dragon Goby may eat some of the fry but will leave most of them and the adults alone), other types of gobies such as the bumblebee goby and knight goby, mollies, glassfish, fiddler and red crabs, platies, and nerite snails.


Many people buy Dragon Fish thinking they are freshwater fish. When kept in freshwater, they will begin to get sick and die within a few days or weeks.  When kept in freshwater with aquarium salt, that extends their life a slightly bit longer, however in a few weeks or months they will still begin to sicken and die.   To successfully keep a Dragon Goby it must be set up in a proper brackish aquarium tank with proper tankmates, diet, salinity, and temperature.

Be sure to keep a tight lid on your tank as well! Although it is not the norm, the violet goby has been known to escape a few tanks.

As they are not easily bred in captivity, the dragon gobies that you will find in your fish and pet shops were likely captured from the estuaries of the Western Atlantic Coast or the Gulf of Mexico.


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