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Diamond Goby Species Overview, Care & Breeding Guide

The diamond goby is loved for its striking orange spots and glittering blue marks on its face. It’s a hyperactive fish that loves to clean sand and decorations, build burrows, and eat shrimp. The best part? It doesn’t quarrel with tankmates and rarely falls sick.

If you’re ready to welcome this fabulous fish to your saltwater tank, this comprehensive guide is just the thing for you.

Species Overview

OriginIndo-Pacific waters
Scientific NameValenciennea puellaris
Common NamesMaiden goby, diamond watchman goby, orange-dashed goby, orange-spotted sleeper-goby, orange-spotted glider goby, pretty prawn goby
IUCN Red List StatusLeast Concern
AppearancePearlescent white body with orange spots and blue spots on the face
SizeUp to 20.32 cm (8 in)
Lifespan3 – 5 years
Reef SafeYes
Tank LevelBottom-dwellers but are known to jump
Water Temperature72-78 °F (22-25 °C)
pH Level8.1-8.4
Water Hardness8-12 dGH
Care LevelEasy
Minimum Tank Size30 gallons
Tank EnvironmentMost comfortable in large live sand beds with many hiding spots
Tank MatesBlennies, cardinalfish, clownfish, damselfish

Natural Habitat

Diamond gobies are natives of the Indo-Pacific waters spanning from the Red Sea by the East African coast across the Indian Ocean and further eastward to Samoa. They are also found in New Caledonia and the southern regions of Japan and Australia.

Originating from the tropics, these impulsive cleaners can thrive in waters of varying degrees of saltiness. They prefer warm temperatures and make their homes in shallow waters.

They live in seaward reefs and clear lagoons, hanging out at the bottom of their territories with their mate in tiny burrows they dig under rubble.

With the IUCN Red List indicating Least Concern, these adorable, modest fish have a stable population.


This goby has the scientific name Valenciennea puellaris. It is a member of the Perciformes order and part of the Gobiidae family. This fish is one of fifteen species in the Valenciennea Genus. However, the Gobiidae family is much larger, with over 2000 species in it, making it one of the largest families of fish in fresh and saltwater.

Interestingly, this fabulous fish has some gorgeous cousins, including the immaculate glidergoby (V. immaculata), the bluestreak goby (V. strigata), and the mural goby (V. muralis).

It is called many names, including the orange-spotted sleeper, diamond watchman goby, orange diamond goby, maiden goby, and similar variations. Some stores also name it the pretty prawn goby and the orange square goby.

Fun Fact: A persistent digger, this goby has the habit of knocking over rock formations and décor. Talk about hyper!


Diamond watchman goby looking at camera

If you are curious about the appearance and behavior of diamond gobies, let’s delve deeper into their characteristics!


Diamond gobies tend to grow 6 to 7 inches long when mature, but they have been recorded to grow up to 8 inches long. Because of their size and look, they are often mistaken for juvenile common blennies.

You can easily find 2-3 inch-long diamond gobies in stores. Larger, 5-inch gobies are rare finds.


This fish is best known for its diamond-shaped spots on its shiny white body, which are arranged in parallel lines.

It has a series of six vertical intermittently connected orange bars on its body, at the termination of which is the characteristic sizeable orange dot. Below these spots lies one horizontal orange stripe.


Like any goby, the watchman maiden has an elongated body and an unpointed head with high-set eyes.

The fish is called an orange-spotted sleeper for good reason – it has specks of orange throughout its dorsal and caudal fins. Its cheek is dotted with light blue lines extending over its gill plate. The eyes have orange rings around them.

Like all gobies, this fish has no swim bladder, so it swims in bursts.

Sexual Dimorphism

In my experience, there’s no way to distinguish a male diamond goby from a female by looking at their bodies. Some believe the females tend to be larger, while others surmise the males have a larger dorsal fin.

Behavior & Temperament

The orange-spotted goby cleans sand, preventing algae growth and detritus accumulation. Aquarists love having it in their tanks for its ability to polish sand to a bright white.

The sand in your aquarium will never get packed down if it’s home to this sifter, but this comes with a trade-off. Its jerky movements tend to create mounds as it sifts through the sand. So, you can expect your tank’s sand to need flattening out every few days.

These are happy to share a tank with any other species if the tank has many hiding spots. They only get aggressive when encountering another sand sifter except for their mate.


The lifespan of a diamond goby is usually around 3-5 years. But it can live longer in the proper water with good care.

Did you know? These are total homebodies! They dig several burrows to retreat to and never swim far from their burrows.

Diamond Goby Care

Diamond watchman goby pair

They are very disease-resistant and easy to care for. They can thrive in an adequately sized tank with other peaceful fish but must be fed twice daily.

Tank Size

A 30-gallon tank is large enough to house one fish of this species. However, it will be healthiest in a 55-gallon tank when it matures.

You must add an additional 15 gallons to your tank for every extra fish you introduce. But if you want two of them, make sure they are a mated pair. Never put this fish in a tank with a sifter from another species. It will trigger quarrels and aggression.

Water Chemistry

These live in salty water, and you can replicate their natural habitat without much hassle.

  • pH Levels: 8.1 to 8.4
  • Water Temperature: 72 to 78° F (22°C – 25°C)
  • Water Hardness: 8 – 12 dGH
  • Ammonia: 0 ppm
  • Nitrite: 0 ppm
  • Nitrate: Below 20 ppm
  • Specific Gravity: 1.020 – 1.025

Check the tank’s water quality every few weeks to ensure your goby remains healthy and lives long.

Tank Environment

Ready to give your diamond goby the perfect home? Learn how with our thorough guide for a safe and joyful environment!


This fish sifts and obsessively cleans sand in its natural habitat and only feels at home around the sand. So, a live sand bed is a must in any tank housing it. Three to four inches of fine sand will keep it active and happy.

Gravel hurts its gills when it turns the sand, so avoid adding any to your tank.


Java moss and java fern are the perfect additions to a live sand tank with a diamond goby. They let through a lot of light and give the tank a striking contrast. Besides, these plants grow in their natural habitat, and these fish often hide behind them.


These thrive in moderate to heavy lighting but don’t demand it, so a regular aquarium light will serve them well. You can use a wide spectrum of light to get the most out of this fish’s beautiful bluish spots.

Note that it sometimes likes to get away from the light, making rockwork and plants essential. Without hiding spots, it will get stressed, increasing the odds of illness and early death.


This beautiful swimmer is reserved in its demeanor and often sneaks into its burrows when not looking for food. So, you must set up plenty of hiding spots that break the fish’s line of sight, like rubble, caves, and rockwork.

Rock formations are every diamond watchman goby’s favorite retreat. But since it digs and moves in bursts, it often dislodges décor and knocks things over. You must set the formations in your tank with aquarium glue and push them deep into the sand.

Reef rocks are a fantastic addition to a tank. But you must leave enough space between décor for them to swim around comfortably.


Sensitive respiratory systems are characteristic of these gobies, so aquarists must keep on their toes in this regard.

Installing an external canister filter is the best way to go, besides using RO-Di water from your local store. You can also install a RODI system to filter the water in your unit. A 25% water change every two weeks is sufficient to keep these fish healthy.

Water Flow Rate

This laid-back fish is happiest in a tank with moderate water flow. So, you can pick up an adjustable powerhead to replicate the water flow of a reef. Of course, a powerhead will also ensurethe water remains oxygenated and your fish remains active and joyful.

Caution: Though diamond gobies hang out at the bottom of tanks, they are skilled jumpers who can leap through the smallest gaps. Keep a tight lid on your tank at all times!

Food & Diet

These carnivores eat small crustaceans and worms when they sift sand in their natural habitat. They love live mysis shrimp and enjoy finely chopped meat and fish.

Offer this species brine shrimp and sometimes flaked and prepared foods. A varied diet twice daily is a sure shot to keep this fish happy and active.

Tank Mates

Diamond goby is friendly, keeping to itself and leading a reserved life of hardcore cleanliness. Naturally, it gels well with peaceful tankmates, but it sometimes picks at the scales and fins of other fish.

Freshwater angelfish, shrimps, damselfish, pink fairy wrasse, filefish, and foxface rabbitfish are the perfect tank mates for a spotted maiden. You can also put one in a tank with clownfish and cardinalfish.

This species never bothers invertebrates, so you can safely put a clam or snail in the tank with it.

Tank Mates to Avoid

A diamond goby is typically the victim, not the aggressor, in a tank with larger marine life. A larger fish may bully this goby or even start chomping away at it. Putting them in a tank with triggers and lionfish is a big no-no.

As mentioned, it is territorial against other sifters, so only add two to a tank if they’re a mated pair.

Interestingly, it sometimes likes to rest on clams and corals, which is rarely an issue.

Common Diseases

This species rarely falls sick in tanks with quality water and a steady food supply. That being said, it is susceptible to a few diseases and cannot tolerate malachite, copper, and formalin treatments. The most common reasons for it to fall ill include:

Disease NameCausesSymptomsTreatment
Velvet DiseaseParasitic dinoflagellateFish may appear lethargic, have cloudy skinQuarantine the affected fish, increase the water temperature
IchParasitic protozoanWhite spots resembling grains of salt on fishIncrease water temperature and apply the hypersalinity method (gradual decrease in salinity)
Saltwater fish diseaseVarious pathogens, including bacteria and virusesCan vary widely but may include lesionsTreatment can consist of antibiotics and antiviral medications

Breeding & Reproduction

Breeding these fish is impossible in a community tank since other fish eat the larvae after the eggs hatch. But they like to be in pairs, so you can easily breed them in a separate tank.

Diamond goby reaches sexual maturity at six months and is a protogynous fish – it changes gender as necessary to procreate. So, if you have two males in a tank, there’s a chance it will change its gender to pair up with the other goby in the tank.

Male-to-Female Ratio

Since these fish are monogamous, the tank must have only one male and one female. A specialist at your local aquarium store could help identify a mated pair.

You could take a chance and put any two of these gobies in a tank together to get some fry. But they could decide to square up and fight to the death.

Mating Ritual

The male chases the female diamond goby around the tank during the breeding period. Eventually, the female will place its eggs on top of a burrow. The male fertilizes the eggs and guards the burrow for three days, at which point the eggs hatch.

Signs of Pregnancy

It’s hard to tell if the female fish is pregnant. The eggs are as small as specks of dust, so pregnancy doesn’t change the shape of the mother much.

Fry Survival

The fry rarely die in captivity with their parents and in the right environment. But the larvae are tiny, so they cannot be fed large foods. So, you must provide them with freshly hatched brine shrimp and copepods until they grow larger.

Breeding Tip: Diamond gobies are more likely to become a pair if one is smaller than the other.

Quick Buying Tips

Spotting a healthy goby of this kind is relatively easy. Take note of whether it is breathing normally, and make sure you watch it eat before bringing it home.

The fish is modest but always alert because it is the prey of much bigger fish. So, if the one you see is sluggish, you shouldn’t buy it. Also, never buy a fish from a tank with ill or dead fish.

A word from FIA

Diamond gobies are beautiful, friendly fish that persistently keep a tank clean and lively. They’re not the kind to fall sick or be challenging to maintain, making them an excellent choice for both new and veteran aquarists.

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