Dragon Fish Goby Care 101 (aka Violet Goby)

The Dragon Goby is a special fish that brings a very different kind of feel to your aquarium.

With their prehistoric and eel-like appearance, they’ve gotten a lot of interest from owners who are looking to break the mold.

But there are a few things you need to know before you consider getting one. These fish have very specific habitat requirements, so you need to be prepared ahead of time.

This guide will cover all the info you need to know when it comes to Dragon Goby care. By the time you’re done reading it, you’ll be ready to get one for yourself!

Species Summary

Dragon Gobies (Gobioides broussonnetii) can be an interesting addition to your aquarium. While not as popular as some other Goby species out there, these fish can be very rewarding to care for.

Due to their skittish behavior and unique water requirements, they can be a challenge to raise in an aquarium. But if you do things right, these fish will reward you with some stunning good looks.

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Dragon Gobies can be found in brackish waters throughout North, Central, and South America. They’re endemic to Atlantic shores as north as South Carolina and as south as Brazil.

They go by many different names. In the aquarium trade, you can see them being referred to as the Violet Goby, Dragon Fish Goby, Dragon Fish, and Peruvian Gobies.

Regardless of what you call them, these fish require some strict care to stay healthy. Their behaviors and appearance will change based on the environment you create for them, so it’s important to understand everything about these fish as you can.


In captivity, the normal Dragon Goby lifespan will be around 10 years old. Many seasoned aquarists have seen their fish live longer than a decade. However, this is still considered uncommon.

Author Note: Many factors contribute to the lifespan of the Dragon Fish Goby, but the biggest is the quality of their water conditions. Dragon Gobies are heavily affected by inferior living conditions, so it’s more important than ever to stay committed to providing the fish with a comfortable and stress-free life.


The average Dragon Goby takes on the iconic silhouette that Gobies are known for. They have long and slender bodies with a round bulbous head. Because of their size, these fish are often mistaken for eels.

An adult Dragon Goby resting on the substrate

At first glance, their fins can be difficult to distinguish from the rest of their body. The anal and dorsal fins run along most of the length of the fish. While the fins aren’t as long as what you’d see with other fish, they’re just pronounced enough to make them look like slender eels in the water!

Pronounced ventral fins just behind their gills are very easy to see. The fish use these fins to get around their environment and cling onto rocks.

The head of the Violet Goby is quite round. When the mouth is open, you’ll notice that these fish have sharp teeth. These aren’t used for fighting. Instead, the fish use them to scrape algae off of rocks.

On the sides of the head are the eyes. They are very tiny compared to the size of this fish. Dragon Gobies have notoriously bad vision. They’re practically blind and will use their ventral fins and mouths to make their way around your tank.

When it comes to differences between males and females, there aren’t many distinguishing features. The way that most breeders will tell the sexes apart is by looking at their genital papilla. Males will have pointed papilla while the female’s genitals will be short and yellow.

One of the most interesting parts of the Violet Goby is its color. Oftentimes, they take on a bland gray or brown color. This is common in the wild.

However, the fish are fully capable of developing some strong colors. When they are kept in ideal conditions, the fish will take on a silvery blue or purple color. It has a metallic finish, giving the appearance of dragon scales!

The base purple or blue color is usually accompanied by splotches of vibrant yellow. This color pattern is a stark contrast to the standard gray or brown you’ll see with unhappy fish. It’s the best way to tell if your fish is getting everything they need!


These fish can get very large. In the wild, the maximum size of a Dragon Goby has been reported at 24 inches in length! That’s considerably larger than most goby species.

However, they stay on the smaller side in captivity. Most won’t get bigger than 15 inches long when living in a home aquarium, but it really all depends on the tank size. Fish kept in large tanks are more likely to reach the higher end of the size spectrum.

Typically, these fish are sold as juveniles in stores. You’ll often see them being sold when they’re only 3 or 4 inches in length.

Dragon Goby Care

Dragon Fish Goby care can be a little bit tricky (especially if you’re going into it unprepared). Not only do they require large tanks to live comfortably, but they have very strict needs when it comes to water conditions.

With that being said, the health and happiness of your fish should always be your top priority. While they can be a handful, but it’s all worth it to see this species thrive and develop their true colors. This section will cover some of the important care guidelines you should stick to.

Tank Size

A tank size of 25 gallons for your Dragon Goby should be the bare minimum if you plan on keeping a single fish. Although, we recommend bumping that up to 50 gallons so that they have room to grow.

As we mentioned earlier, Dragon Gobies are not small and will need a relatively large tank to keep them healthy.

The tricky part of caring for a long fish like the Violet Goby is that there needs to be ample room for swimming. Not only do you need to consider volume, but you have to take length into account, too. For Dragon Gobies, we recommend that your tank is 4 feet long for a single specimen.

Now, if you plan on keeping a pair or group you’ll need to go a bit larger. As a good rule of thumb, provide at least 25 gallons of space per fish. These fish can get a bit territorial, so you’ll need a tank that’s about 6 feet long to ensure that your pair has their own space.

Author Note: In our experience. the Violet Gobies that have lived the longest have all been kept by owners who give them really large tanks. It’s clear that the extra space makes a big impact on their overall health.

Water Parameters

Dragon Gobies live in brackish waters in the wild. This means their habitat isn’t as high in salt content as the open ocean, but it has too much salt to be considered freshwater.

You need to analyze water contents regularly to keep the conditions good. These fish are sensitive to chemical changes. This includes high concentrations of ammonia and nitrates. We recommend doing a 10 to 15 percent water change every single week to keep things optimal.

Check out these important water parameters you need to follow to keep your Dragon Gobies healthy.

  • Water temperature: 72°F to 82°F (we recommend 75°F ideally)
  • pH levels: 6.5 to 8.5
  • Water hardness: 10 to 20 dKH
  • Specific gravity: 1.006 to 1.008

Since this species can be particularly finicky when it comes to water conditions, it’s important to make sure you’re in tune with the status of your tank at all times. Perform frequent water checks and take any subtle change seriously.

Setting Up Their Tank

The environments these fish call home are muddy and swampy. The Violet Goby is found in bays and estuaries. You can aim to recreate that swampy environment in your own tank with the right decor.

The bottom of your tank should have a dark sandy substrate. These are bottom-feeder fish that will spend most of their time in the lower portion of your aquarium. They’ll also suck up sand to sift out food.

Gobioides broussonnetii sucking up substrate at the bottom of the aquarium

This means large gravel can pose a significant health risk. Soft and fine sand is the safe and logical choice.

Something that a lot of aquarists recommend is enriching the sand with pieces of aragonite (here’s a brand we recommend). You can do this by mixing it with the dark sand to ensure that light doesn’t reflect off of the crystals and harm the sensitive eyes of the fish. As a bonus, aragonite can help maintain the water’s alkalinity and hardness.

On top of your sand and aragonite floor layer, place several plants, rocks, and caves. These fish are very timid and need plenty of places to hide whenever they need some space.

Don’t be afraid to get creative and introduce anything that can provide shelter. A Dragon Goby tank is a great way to mix up plant varieties and try out new things. Anubias, Java Fern, Vallisneria, and more are all good plants to try out.

Potential Diseases

The Dragon Fish Goby, while hardy, can be affected by diseases just like any fish. Beyond the usual Ich and stress-related issues, there are a couple of ailments that are common with this species.

The first is fin rot. Even though their fins aren’t tall like other species, Dragon Gobies certainly have a lot of fin space that can be affected by rot.

With this condition, the fins become decayed and raggedy. It can cause tears and extreme discoloration.

The problem can get so bad that the decaying continues all the way to the base of the fin where it can cause bacterial infections. In most cases, fin rot is a direct byproduct of stress. Your fish could be affected by a poor diet, substandard water conditions, and more.

Another common ailment is Columnaris, or cottonmouth. It is similar to fin rot in the sense that it causes decay. However, cottonmouth affects the gills. The disease can also cause ulcers on the skin.

Columnaris has the potential to be fatal, so it’s important to provide treatment as much as possible. You may be able to heal the issue with antibiotics and antifungal treatments.

Author Note: The most effective way to prevent your fish from getting these diseases is to simply take care of the water. An aquarium with dirty water is a breeding ground for various illnesses. It’s comparable to having thick smog all throughout your home!

Food & Diet

Dragon Gobies are omnivores and usually rely on scavenging to eat in the wild. They’ll continue that scavenging behavior in the tank. However, you need to provide them with a well-rounded diet to keep them healthy.

The interesting thing about these fish is that they have very narrow throats. Despite their size, they actually have difficulties eating larger food. So, you need to keep things relatively small.

You can feed them flakes, small sinking pellets, and algae wafers as their primary source of dried food. We recommend supplementing that with frozen, freeze-dried, and live foot, too.

Bloodworms, tubifex worms, baby brine shrimp, and small pieces of vegetables are all good options that are nutritionally-rich and enjoyable for them to eat.

The ideal feeding schedule for the Violet Goby is once per day. Avoid overfeeding by limiting them to as much food as they can eat in a couple of minutes (any more is too much).

Behavior & Temperament

These fish have a somewhat negative reputation. They’re sometimes called aggressive or semi-aggressive fish by aquarists in various forums online.

But the truth is, they usually don’t pay any attention to others in the tank. They’re more scared and timid than anything else!

While they have sharp teeth, they’ll rarely attack fish that aren’t bothering them. The only time you might see signs of aggression is if they’re breeding or have established territory they want to protect.

As far as their activity level is concerned, the Dragon Fish Goby is largely nocturnal. They’ll spend most of the day hiding out in dark spots and become much more active at night.

If you observe them at night you’ll often find them sifting through the substrate for bits of food.

Dragon Goby Tank Mates

Contrary to popular belief, there are a number of Dragon Goby tank mates you can consider.

Peaceful brackish fish can share the same space with this species without any issues. Just avoid any aggressive species that will cause trouble.

Medium-sized (aka similar-sized) fish are best. You want to avoid anything that could be potentially viewed as food for the Dragon Goby. Here’s a collection of suitable tank mates:


If you know the sexes of your fish, breeding Dragon Fish Gobies isn’t too much of a hassle. Though, you will need to perform certain tasks to initiate the process.

Start by grouping 3 female fish to 1 male fish. The male fish will often breed with all of the females in one day. To start the breeding cycle, decrease the amount of food you provide for about a week. Then, condition the fish with a high-protein diet of live food.

Now, lower the salinity levels to about 1.004. The following day, quickly raise it to about 1.023. This will trigger the breeding cycle, causing the male to spawn with the females.

The female specimens will lay several eggs. After she’s done, remove her from the tank. Once all of the females are out of the tank, you’ll see the male Dragon Goby keeping a watchful eye.

He’ll protect the eggs for up to 2 days, which is when they will hatch. After the eggs have hatched, remove the male from the tank and let the fry grow on their own. You can feed them infusoria and simple algae for a month until they are ready to move onto baby brine shrimp.            

Now You’re Prepared

Now that you’ve read this guide, you’re ready to get one of these fish for yourself. While Dragon Fish Goby care can be a little bit intimidating at first, it’s all about having the right knowledge and being persistent.

Because of their unique requirements, this species is one of the more rewarding fish to care for. We’ve heard this exact statement from countless owners over the years!

Feel free to send us any additional questions you might have about the Violet Goby. Not only do we enjoy helping, but your questions will help us make our guide more useful for future visitors.

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