Engineer Goby – Complete Care Guide, 4 Tank Mates & Lifespan

Engineer Goby

Last updated on July 1st, 2022 at 11:08 am

The engineer Goby, Pholidychtys luecotaenia, has a black body with a white straight stripe. They are extremely hardy and very peaceful. They can be kept with other peaceful fishes in reef tanks setting but may become aggressive against various other blennies, gobies, or dartfish in smaller-sized tanks.

Engineer Goby has the tendency to remain at the bottom of the tank at all times, filtering and sifting through the sand. This goby is likewise a known jumper, so a securely fitting lid is advised.

Diet needs to include a selection of frozen or live Mysis shrimp and vitamin-enriched brine shrimp 1-2 times daily.

What is the Engineer Goby?

Engineer Goby has a few names, some of which are Convict Goby and Convict Blenny. This serves as an addition in identifying these remarkable fish because there is another fish type that also is also called Convict Blenny, Priolepis Nocturna. And this fish s actually the real Goby.

Engineer Goby is in fact member of its own family, Pholidichthyidae. And surprisingly enough, they are very closely related to the practically completely freshwater Cichlidae family, which includes Angelfish, Oscars, and others.

Like the majority of Cichlids, Engineer Goby are predators that feed on anything little and sufficient enough to be overpowered and consumed. Although they are very peaceful, they are a danger to smaller-sized tank mates, particularly small, thin fish.

Just like Cichlids, Engineer Goby are somewhat territorial and sociable. They rarely spat amongst themselves. Groups of Engineer Goby form swarms of dozens and even thousands of people in the wild that interact to develop interconnecting passages that is many meters long.

Engineer Goby

This continuous construction behavior is what offers Engineer Goby their most common name. These fish simply aren’t comfortable unless they have structures to delve under. When young, they are solid black with a silvery-white stripe. They look fairly a bit like the mildly poisonous Coral Catfish (Phetusus angularis).

As they grow, the horizontal stripes combine into lotches and ultimately vertical bars and Engineer Goby spend less time swimming exposed.

Although they aren’t especially scarce, there is very little information out there on these striking fish. So let’s study how to take care of this “goby!”.

  • Common Names: Engineer Goby, Convict Goby, Convict Blenny.
  • Scientific Name: Pholidichthys leucotaenia.
  • Origin: IndoPacific; Indonesia, Fiji
  • Length: 12 inches.
  • Tank size: 55 gallons
  • Behavior: Peaceful; Social
  • Ease of care: Very easy

Engineer Goby Appearance

Engineer Goby

A small and young engineer goby fish appears a lot like a younger saltwater catfish. As soon as they develop, their whole appearance changes. A grown-up engineer goby leaves behind one solitary straight stripe in neon color and accepts a yellow and black striped pattern.

This pattern appears a great deal like red stripes from your houses in prisons which’s where their name convict blenny come from.

In the first couple of years of their adulthood, the engineer goby fishes sport this black and yellow pattern. In addition to the magnificent pattern, adult engineer goby is a long, slim shape that resembles a lot like an eel.

More details on Engineer goby

The engineer goby is definitely one of my favorite saltwater fish. They have been kept in my display tank for many years.

They are one of the most economical fish in the saltwater aquarium hobby, with a cost below $10, most of the time for a small juvenile fish.

As a juvenile fish, the engineer goby looks a lot like adolescent saltwater catfish.

The catfish species they look like (and can commonly be mistaken with) have poisonous spines, so it is believed that the engineer goby imitates this look as a protective adaptation.

Pholidichthys Leucotaenia Care Guide (Convict Blenny)

As grownups, the engineer goby entirely alters their appearance. The single, horizontal neon red stripe disappears and is replaced by a yellow and black striping pattern.

They become this brand-new coloration pattern over the first year of their lives. Along with having these interesting stripes/bars, adults are long, slim, and also eel-like in shape. In reality, your non-fishy good friends that look at your fish tank are really likely to believe they are, actually eels.

Then, once they understand that, you can additionally confuse them by letting them know that they really are blennies, not goby. Their Latin name is Pholidichthys leucotaenia.

If you like, you can bore your good friends by educating them that they are not eels, they are engineer goby.

Engineer Goby Care

In General, Engineer Goby is very easy to care for. They are hardy, excited eaters, and also not too big. However, there are a couple of problems that we will attend to below!

Aquarium Size

The Engineer Goby commonly reaches an optimum size of 12 inches in home fish tanks but occasionally enlarges in the wild or with extreme age. They are understood to reach 11 years of age and up to 18 inches, however, this is really unusual.

A 55-gallon aquarium is an outright minimum for grownups. Young Engineer Goby (2-3 inches) can be kept in smaller storage tanks (20+ gallons) till they are grownups. Being predators with a systematic way of eating, larger water quantities are advised.

Smaller-sized tanks change in specifications really quickly and a single overfeeding occasion can trigger radical changes in ammonia and nitrite.

Be aware that like numerous eel-shaped fish, the Engineer Goby is an escape-artist in training. Particularly when young, which is when they spend more time free swimming. During the night your Engineer Goby may attempt testing the bounds of the tank.

Loosened covers or holes for pipes as well as wiring are all possible escape paths for these active fish. Be sure that the tank is well protected to avoid a depressing discovery the following morning.

Water Conditions

Engineer Goby is one of the even more beginner-friendly marine fish. They do not have detailed requirements in the way of water conditions as well as choose conventional aquatic parameters.

Temperature levels must be a little high, be sure to keep them in between 75 to 82℉ as their native range is around equatorial island groups such as Indonesia. And while you intend to keep ammonia, nitrite, and nitrate as near 0ppm as possible, Engineer Goby aren’t especially sensitive to small quantities of these compounds.

What is important is to make sure that your water is without high bacteria/fungal concentrations. The Engineer Goby is a scaleless fish and even worse, a digger.

Scaleless fish do not have the protection supplied by hard scales. Wounds created by battling, predators … Or scuffs from excavating … Are really susceptible to getting infected.

If it instantly dashes back to its burrow in a panic for some reason, an Engineer Goby can conveniently get a scratch from a coral frag. And if the water has greater than normal concentrations of bacteria, fungus, viruses, etc, due to poor specifications … Infections are most likely ahead up.

Worse, scaleless fish are highly conscious of medication doses. Fish scales slow the uptake of medicines normally. When treating scaleless fish, it’s much better to make use of 1/2 of the common dosage unless you have actually dealt with these fish before for the very same agent.

Diamond Gobies (Sandsifter Goby) Care

Obviously, 1/2 dosage may not suffice to treat the infections. Or you might need even more time than normal for the disease to run its program. Regardless, a quarantine tank is a way to go with handling a sick Engineer Goby.

Water conditions for Engineer Goby

  • Temperature: 75 to 82℉.
  • pH:0 – 8.4.
  • Specific Gravity:020 to 1.025.
  • Alkalinity: 8 to 11 DKH.
  • Ammonia, Nitrite, Nitrate: As near to 0ppm as feasible.

Aquascaping for Engineer Goby

If you choose to get an Engineer Goby you’ll need to put a little additional idea into how you layout your tank. They get their name from their behavior of structure huge tunnels under and throughout coral rubble. Although they aren’t precisely small fish.

They can go up to 6 lbs of sand a day in nature once they decide they wish to dig a deep tunnel! And these tunnels can be several meters long.
Unfortunately, it is common for an Engineer Goby to get caught and die in reef tanks.

Coral rubble can shift instantly, pinning the Goby in position until it starves. Worse, these fish like to vanish for days and even weeks at a time. You may not also realize it entrapped itself up until it’s much far too late.

Your aquascape requires to be secure enough to withstand some weakening as well as scrambling around. In short: you ought to think like an engineer or architect on your own! A determined foot-long Engineer Goby can move the base of live rocks considerably so be sure none of it is delicately well balanced.

Use glue to bond live rock pieces, reef frags, and also various other items of the aquascape to each other. In this way, it’s really not likely the Engineer Goby will certainly engineer a collapse on you.

The substratum ought to likewise be something the Goby can dig through. Sand is excellent for juveniles. While it doesn’t constantly permit them to tunnel the young Goby typically simply burrow into it.

When the Goby builds its tunnels, as adults stick to large-grained sand, coral, or gravel rubble as it holds its form better. If your substrate isn’t very thick (less than 2 inches) make sure that your rock and coral are close (but not touching) to the glass bottom of the tank.. That way, any changes as the Goby undermine the structure are minor.

Finally, live rock structures with gaps, cavities, and holes are much appreciated. By doing this you’re much more likely to see your Engineer Goby above ground as it knows it has a boundless variety of possible escapes if it feels intimidating.

Interesting behavior Engineer goby

Because of their digging behavior, engineer goby fascinate me. They are shy types of fish and invest the majority of their time in tunnels that they dig in your sand bed. What I love about them is that they don’t just construct one set of tunnels to construct their desire house as well as retire, but on the contrary, they never ever appear to stop excavating. They are continuously excavating and also re-digging tunnels in your sand.


These fish spend almost all of their time in the sand, excavating, so they are best kept in a tank with a live sand substrate or deep sand bed. They also use some tiny debris or crushed aragonite for their burrows, however many of the excavating take place in the sand.

At feeding time, they will dart up as well as out of their burrow to get hold of some food.

Ocellaris Clownfish Care Guide

Reproducing engineer goby in the saltwater aquarium

Engineer Goby

According to Matt Wittenrich, in The Complete Illustrated Breeder’s Overview to Marine Fish-Tank Fishes, the found convict worm blenny is a relatively simple fish to reproduce in the home aquarium. Since these fish are low-cost and mostly marketed as juveniles, for just a few dollars, the most straightforward means to produce a mating pair is to get 5 to 7 specific juveniles as well as allow them to couple off by themselves.

Spawns are reported to be relatively irregular, happening simply as soon as or twice annually, but are of a reasonably plus size, averaging 400 to 500 larvae (again, according to Witt).

Although I have actually kept these fish in my tank for several years, I have actually regrettably never observed spawning, but right here’s why I’m so obsessed with the idea.

Engineer goby is the cichlids of the sea. As soon as the larvae hatch from their eggs, they will leave the burrow, under the mindful watch of their parents. Yes, like freshwater cichlids, both parents will supervise, protect as well as even safeguard the larvae. I can’t wait to wake up eventually to see 500 larvae swimming around my engineer goby!


The found convict blenny is carnivorous in nature — it’s a meat eater and also should, therefore, be fed with premium weighty foods, like Mysis shrimp, Artemia (brine shrimp), live black worms or other weighty fish and shellfish.

They are shy fish, so they frequently get startled by the various other fish in the tank or rapid movements, so be certain to be slow-moving, quiet, and calm while feeding these amazing fish. They will also benefit from being fed two times a day if you can handle it.

At feeding time, these fish will certainly dart out of their burrows to order the yummy tidbits of food out of the water column as they drift by.

Are they reef safe?

Engineer Goby

Yes, the engineer goby is reef secure, yet you must take a few factors into consideration. As pointed out previously, they will certainly be constantly digging around under the surface of your sand bed. They may actually cause your reef rock pile to sink when they do that. They could even end up causing your structure to collapse a bit if your rocks sink and move.

So if you intend to keep this remarkable fish in your tank, it is most likely best if you can be certain your reef framework starts all the way under glass. Simply put, place the structure of the reef on the cheapest framework you can, not on top of the sand.

The goby will dig under those rocks and the weight could collapse the tunnel and topple your rock tower if you do.
There are also records of the found convict blenny eating fish or shrimp small enough to suit their mouths. That’s probably true of almost any fish, so keep an eye out for that.

Personal Observation

I’ve been fortunate to have kept a number of different individuals in my tank throughout the years. Along with what I have shared above, I would certainly like to add two observations from the individual in my tanks.

Prone to saltwater ich

It is my observation that this species of fish is reasonably vulnerable to be influenced by saltwater Ich. Even more than one individual has actually had issues with this bloodsucker, seemingly ‘unexpectedly’ and while others around them didn’t.

Do not take this observation too far — it’s simply a personal story. I urge you to keep an eye out.

The Blackbar Soldierfish (Myripristis jacobus)

I guess that the fact that they spend ALL OF THEIR TIME in the sand bed puts them always in distance to the hatching phase of the lifecycle.

Intolerant of temperature swings or periods of low flow

I do not understand if this is an axiom about this fish, but I have actually personally observed that the fish is especially at risk to death during a power interruption.

My engineer goby was the canary in the coal mine, during a power failure, and was the first animal in my tank to have died due to complications from the loss of power.

Engineer goby tank mates

Choosing perfect engineer goby tank mates takes just a little bit of thought, however, it is primarily straightforward. Engineer Goby is a very peaceful and social fish. They are carnivores and opportunists.

Anything slow and small enough to be consumed is in danger from them. And also they don’t specifically have tiny mouths, either. Little, thin fish, like Firefish (Nemateleotris sp.), smaller-sized Goby, and young Blennies are at risk of becoming a meal. As adults, they have a tendency to be thick enough to not be an easy meal.

Smaller-sized saltwater shrimp are also in danger of being consumed. But grownups of the larger types, such as Banded Coral Shrimp (Stenopus hispidus) are fine, as are other large shellfishes such as Arrowhead Crabs (Stenorhynchus sp.).

Starfish, Snails, Sea Urchins, Clams, and various other unsavory invertebrates remain in no danger from an Engineer Goby. They may get pushed around a bit if they get too close to the burrow entrance!

Any fish too large to be easily eaten will make a fine tank mate. This includes Damselfish, Clownfish, Angelfish, Tangs, Dwarf Lionfish, and also other typical aquatic community fish.

Also, some aggressive fish like Triggerfish and larger Angels can work since the Engineer Goby will certainly invest nearly all of its time around and in its burrow. Avoid keeping them with aggressive burrow-dwellers like Moray Eels.

Engineer Goby are quite social, both as juveniles and adults. When free swimming, the juveniles will stick together in schools. As grownups they develop swarms of thousands of people, both adolescent, and grown-up, that share their passages and also contribute to them in time.

Perfect engineer goby tank mates

  • Damselfish, Clownfish, Angelfish, Tangs, as well as other marine Area Fish.
  • Other Engineer Gobies
  • Larger Crustaceans, Snails, Starfish, Sea Urchins, and Other Invertebrates
  • Corals, Sea Anemones, Sponges, as well as other Sessile Microorganisms.

Bad engineer goby tank mates

  • Fish small enough to be eaten (Firefish, tiny Blennies, Goby, etc)
  • Tiny shrimp or crabs
  • Aggressive tunnel dwellers (Moray Eels)

Conclusion on Engineer Goby

If you have a community tank that is at least 40 gallons or a dedicated 20-gallon tank for a set, a deep sand bed as well as a few bucks in your pocket, you can include this remarkable, perpetually busy, and shy fish.

They are just one of my favorites, I wish you will certainly enjoy them as well.