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Engineer Goby Care & Info

Engineer Goby (Pholidichthys leucotaenia) Care & Info

It looks like an eel, but isn’t. It’s known as a goby or blenny, but is neither. When young it resembles a coral catfish, but that’s also not what it is. What fish could we possibly be talking about? Why, Pholidichthys leucotaenia of course!

Keep reading for everything you need to know about keeping the confusingly named engineer goby in your saltwater aquarium. 

Name (Common, Scientific)

Engineer goby, convict blenny, Pholidichthys leucotaenia

Minimum tank size

50 gallons

Minimum group size



72-78 °F





Difficulty level


Engineer Goby (Pholidichthys Leucotaenia) Description

This species is also known under the names ‘goby’ and ‘blenny’ because it is, in fact, closely related to real gobies and blennies. However, it’s a member of the Pholidichthys family, which contains only one other species. (If you’re looking for a real blenny, may we suggest one of our personal favorites, the lawnmower blenny?)

As with many fish, the engineer goby’s appearance varies greatly with age. A juvenile engineer goby does actually resemble a real goby a bit, featuring horizontal white bands on a black body. With age, the fish takes on a more eel-like appearance and its horizontal markings shift to vertical bars. 

The engineer goby can reach a maximum size of 13-14”, which is something to be kept in mind! It’s not possible to visually sex these fish, so if you’re interested in breeding you’ll have to get a group and hope there’s at least one pair in there.

Engineer goby care & info

Engineer Goby (Pholidichthys leucotaenia) Aquarium

Due to their large adult size, you should be looking at an aquarium of 50 gallons or up if you’re interested in keeping an engineer goby. 

Now, the most important thing to keep in mind about these fish is that they got their common name ‘engineer’ for a reason. They absolutely love burrowing and redecorating the aquarium and will spend much of their time doing so. If you like a very neat and tidy tank, this species is definitely not for you.

Because engineer gobies enjoy throwing substrate around and digging below rock, you’ll have to take some precautions if you’d like to keep this species. All rock should be extremely stable, preferably resting against the walls of the aquarium. If it can topple over, it will, which can be disastrous for your tank. Additionally, although the engineer goby is reef friendly, it will spray any corals that are close to the bottom of the tank with substrate and possibly even bury them. This is unfortunately often fatal to the coral in question, so keep them high enough to avoid issues.

TIP: When aquascaping your aquarium be sure to add the rock structure before the sand. This ensures all of the rocks are stable on the bottom of the glass. This will help prevent your Engineer gobies from making the rock structure a thing of the past: if you don’t take measures, they’ll burrow under it and cause it to topple.

Engineer Goby (Pholidichthys Leucotaenia) Compatibility

Although the engineer goby is generally considered peaceful and not prone to getting into brawls, adult specimens might become rather protective of their burrows. Additionally, you’ll have to keep in mind that despite their peaceful nature these are still predators. If something fits into an adult engineer goby’s mouth, it will inevitably end up in there. 

As such, choose your tankmates with care. They should be peaceful and on the larger side to prevent them from getting eaten. You might want to somewhat avoid other burrowing species. 

When it comes to group size, consider that wild engineer gobies move in large schools. Keeping them as at least a pair is recommendable, though it has been noted that one should always introduce all of the engineer gobies at the same time to avoid bickering.

Feeding Engineer Goby (Pholidichthys Leucotaenia)

Once you’ve made peace with their interior decoration habits, caring for an engineer goby is luckily not overly challenging. These fish are carnivorous and require a meaty diet; luckily they’ll gladly gobble up pretty much anything you present them with. 

Twice daily feedings of mysis shrimp and brine shrimp are good options, as are cut up bits of seafood. 


The eel-like engineer goby is a fascinating addition to a beautiful saltwater aquarium. Are you dreaming of having your own (reef) tank in your home or office? Contact us with your ideas and we’ll see how we can help you out!

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Marijke Puts

Hey! I'm Marijke, FantaSEA's resident blog writer. I'm a full-time pop science author, part-time PADI diver and snorkeler, and have been keeping fish since I was a kid. When I'm not writing fish care guides, you can usually find me underwater or trying to figure out how to fit more tanks into my house.

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