The dragon goby, also known as violet goby or Gobioides broussonetti, is ideal for fish keepers that prefer bottom-dwelling species.
It has been gaining popularity for its belligerent face, beautiful purple color, and eel-like appearance. As a brackish water fish, the dragon goby is best-suited for those with an intermediate or advanced level of aquatic experience.
What does it take to create a habitat that will house these unique fish? Keep reading to learn everything you need to know to successfully care for, maintain and breed your dragon goby.
Dragon Goby Stats
|Listed tank sizes are the minimum|
|Tank:||20 – 50 gallons|
|Strata:||12 to 20 inches (30-50cm) 12” being common|
|PH:||48 inches (55 gallons) longer is better than wide|
|Hardness:||7.5 to 8.0|
|Temperature:||A 1 percent addition of salt is recommended as these fish are found in brackish water. This can be accomplished by adding 7.5 TSP of sea salt/ 10 gallons (10g/10 L) on a hydrometer; the reading should be between 1.005 to 1.010 specific gravity.|
Dragon Goby: Origin and Appearance
Sometimes called the blue dragon eel or dragon loach, the dragon goby is a member of the Gobiidae family. Its native range is from the Atlantic coast of South Carolina to the Gulf of Mexico and down to Brazil, making it one of the most widespread fish available in the fish-keeping world.
Dragon gobies thrive in brackish water. They are found in tidal estuaries and bays where freshwater rivers run into the ocean. Their ideal habitat is muddy bottoms where they can burrow and hide during the daytime.
Dragon gobies are nocturnal and will emerge from their burrows at night to feed. They are sometimes accidentally caught by fishermen.
The typical dragon goby size found in aquariums is about 12 inches. In the wild, however, a full grown dragon goby can reach 24 inches, so your fish has the potential to grow quite large. The average lifespan is 10 years.
In appearance, the dragon goby has the classic, eel-like goby body with a round, bulbous head. A long, low fin stretches most of the length of its back to a slim, tapered tail. The anal fin is similarly shaped.
Its ventral fins are adapted to help the dragon goby cling to rocks and grass as it hunts for food.
If you look into a dragon goby’s mouth, you will see a set of very sharp teeth. These fish are scavengers and use their teeth to filter small worms, snails, crabs, and other foods from the sand and mud in which they live.
Dragon gobies often are dull brown or gray. When well-fed and cared for. However, they can develop a deep, iridescent violet, purple, or blue color that is very appealing. Some have compared this coloring to dragon scales, hence their name.
This is one goby species where it is quite difficult to tell male and female fishes apart. Experienced fish keepers and breeders can usually tell them apart by their genitalia. Males have pointed papilla, while females will be shorter and yellow.
Like most gobies, the dragon goby is very territorial. It is difficult to keep more than one in the same tank. At the same time, it is not an aggressive fish and will not fight other species unless attacked or provoked.
Dragon gobies are quite difficult to breed. Most that are sold in pet stores are captured from estuaries of the southern United States.
Proper Dragon Goby Care
When kept in freshwater, the fish begin to show signs of stress such as loss of color or sluggish behavior. If not placed back in brackish water within a few weeks, they will die.
Dragon gobies are scavengers by nature and take their meals off the bottom. Because they sift food with their mouths, they need something to chew on that will keep their teeth from overgrowing their mouth.
They do equally well on frozen or freeze-dried choices, including:
- Blood worms
- Black tubifex
- Sinking algae wafers
- Sinking flake food
- Very small snails
Remember to size the food to a dragon gobies’ tiny mouth.
Since dragon gobies live near the tank’s lower strata, feeding them means using foods that will sink quickly past other fish in the aquarium to the bottom.
They do like standard fish foods like freeze-dried flakes, but since flakes will float until they gain enough water to sink, flakes can be gobbled up by the upper and mid strata tank mates before making it down to the knight fish feeding zone.
As a nocturnal fish, you can feed them once a day before you turn out the lights. Some keepers will train their dragon gobies to feed during daylight so they can watch them eat.
– Tank Size and Water Conditions
Proper care for dragon gobies starts with good, clean, brackish water. You can create this using chemical-free water with salt added at a ratio of 7.5 TSP of sea salt/ 10 gallons (10g/10 L). When tested on a hydrometer, the reading should be between 1.005 to 1.010 specific gravity.
The ideal dragon fish tank is a horizontal format with a capacity of at least 20 gallons for a single dragon goby, with 50 gallons being ideal for long-term housing. If you plan on having more than one, plan on a 100-gallon tank at the minimum to give each fish ample territory. Having more than two dragon gobies will just result in battling or dead fish unless you have very large [200 gallons and up] setups.
A heating system sized to your tank is essential to keep the water in the 75 F to 80 F range. A heater is preferred over a heat lamp. If you choose to keep your dragon goby as a nocturnal fish, the water should stay in the temperature range night and day.
Water quality is critically important. In the wild, these fish go through tidal changes every four hours, which refreshes their environment with new fresh and saltwater.
Dragon gobies are very sensitive to ammonia and other contaminants that settle to the bottom of an aquarium from fish and food waste. These toxins can quickly bring your fish to disease or death.
If you observe your dragon gobies acting like they are gasping, this is a good indication the water quality is off or too dirty.
The best way to replicate their natural conditions is with a good filtration system and a minimum 10 percent to 15 percent water change every other week or as needed. Maintain a pH range of 6.5 to 8.5, and you will have ideal water conditions for your gobies and tank mates.
– Tank Setup and Decoration
Since dragon gobies spend most of their daylight hours hiding in mud, they need a substrate they can hide in. Good mud is hard to find, so standard aquarium sand is a great substitute.
Add at least three or four inches to the entire bottom of the tank so that your fish have ample room to burrow under.
If the tank mates you add to the dragon goby habitat need rocks or other hardscapes, add them sparingly. And avoid sharp decor such as coral. It can scrape the gobies’ delicate sides and open them to infection.
If you create nooks and caves at the bottom, your dragon gobies will make use of them. Some keepers use their tendency to hide to their viewing advantage by tilting up a slab of rock against the front wall of the tank. The dragon goby will hide underneath the rock but be visible to anyone observing.
Pieces of mangrove or artificial wood can also be placed in the bottom for shelter and variety.
Plants are great additions to a goby habitat as long as you can anchor them securely. Great plants that can tolerate brackish water and provide both color and shelter include:
- Java moss
- Java fern
- Marimo moss balls
Keep your plants securely on the bottom by using ring-type plant anchors when you first add them to the aquarium. This will keep your dragon goby from inadvertently digging them up as they root and sift the bottom.
With some artful aquascaping, you can design a habitat that is ideal for your dragon goby and a beautiful recreation of their natural surroundings.
– Tank Mates
Dragon gobies will strongly defend their territory, but they pretty much ignore the rest of the tank as long as their tank mates do not pester them or spend too much time on the bottom.
For this reason, other bottom-dwelling fish and non-fish species are not good choices. Here are a few species that make great tank mates.
Knight gobies: The knight goby has very similar needs for water condition and quality but is surprisingly not aggressive with other goby species as long as there is room for them to spread out. They will not fin nip each other.
Glass fish: The glass fish or Indian glassy fish is a delicate, silvery fish that is peaceful and does well in small schools. It does well in brackish water and grows up to three inches. Avoid the painted varieties of glass fish. They have been injected with dye to impart the colors and are susceptible to disease.
Guppies: Guppies are the closest thing to universal tank mates. They are small, peaceful, love their schools, and are available in a wide range of subspecies and colors.
Swordtails: Red or green swordtails are wonderful tank mates for brackish water tanks. They are peaceful, do well in schools, and their bright colors add visual appeal to the habitat. Many breeders have created colorful varieties, so you have lots of choices with this easy to care for species. They can grow up to 5 inches in length and can be a problem for small species such as guppies.
Mollies: The shortfin molly or common molly is a small, yellow-finned fish that thrives in warm brackish water. There are quite a few bred varieties, so, like guppies, you have ample choices. They love vegetation and will get along with anything not large enough to eat them.
Platies: Similar to guppies and mollies, the platy is brackish water-adapted species with many colorful varieties to choose from.
Rainbowfish: This species comes from similar estuary habitats in Australia, New Zealand, and New Guinea. It is very colorful, almost metallic, but larger at nearly 4 inches. It is a great pairing with swordtails, but not for smaller species.
Snails: Both Nerite and Malaysian trumpet snails do well in brackish water. They help with algae control, and unless they are small enough to fit into your dragon goby’s mouth, they will not be bothered.
A selection of colorful tank mates will round out your dragon goby aquarium and provide wonderful visual appeal.
Goby breeding is one of the most challenging fish-keeping endeavors. It can be accomplished; it is rarely successful with any but the most determined hobbyist.
Their breeding is not an issue for species availability as dragon gobies are not threatened, and there is an active wild fish trade.
Much of the information about breeding dragon gobies comes from very few successful sources. Wikipedia has a good, concise reference on dragon goby breeding, but here is an overview of what it takes to breed them.
- Start with a very large aquarium. You will be housing one male and several female dragon gobies.
- Sexing gobies can be difficult. Enlist some professional help if you are not sure whether you have a male and several females. Adding two males to the tank will result in fighting.
- Starve them for a few days before you bring them together in one aquarium, then feed them sinking live or chopped meaty protein foods.
- Trying to vary the salinity of the water over a few days. Reduce it, then increase it slightly heavy, then bring it back to true.
- Make sure the breeding aquarium has a deep sand bottom and many hiding places for the females to hide, preferably outside of the male’s territory.
If they are mating, the male will breed with several of the females over a day and night. He will build a nest to deposit the eggs in. If you are not observing your fish at night, this is a sure sign that they are breeding.
The male will guard the eggs for a day or two until they hatch. Once they have, the adult fish should be put back into their home tanks.
Feed the fry infusoria or single-cell algae [green water] for a month or so, until they are large enough to feed on brine shrimp nauplii.
If you are unsuccessful in a breeding attempt, find an experienced goby breeder and see if they will mentor you.
Here are some key takeaways to keep in mind:
- Maintain a brackish tank environment that mimics the dragon goby home waters.
- Large, horizontal format tanks are best for this species. Twenty gallons is good for a single fish and 50 gallons or more for two fish. Remember, they can grow to as long as 24 inches and live up to 10 years.
- Keep the water between 75 F and 80 F with a heater preferred over a heat lamp.
- Keep the aquarium water fresh and clean with good filtration and bi-weekly water changes.
- Use at least three inches of sand as a substrate, so your dragon goby has a place to burrow.
- Anchor all plants in the tank so that the dragon goby does not accidentally dig them up.
- Mangrove roots, fake driftwood, and smooth rocks are all good hardscape choices.
- Design caves and places for your dragon goby to hide.
- Tankmates should live in the mid or upper strata of the tank.
- Select tank mates that are about the same size as each other to minimize predation.
- Breeding dragon gobies is a challenging task that requires a large aquarium and several female fish.
- Tricks to induce the fish to breed include starving them for a few days, increasing and decreasing salinity, and feeding them living foods after the starvation period.
- If the male makes a nest, it is a good indication the fish are breeding.
- Sinking alive, dead, or pelletized food will keep them fed and happy.
Dragon gobies highlight the challenges of keeping sensitive fish in brackish water environments. If you can overcome them, you will be building your skills and experience as a keeper. The rewards for you will be a unique tidewater habitat of lively, colorful fish that will reflect your artistry and expertise.
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