Spotted Blue-eye

Spotted Blue-eye key facts

Care level

Intermediate

Lifespan

2-3 years

Size

Up to 3.8cm SL

Temperature

21〜28℃

Diet

Fine dried foods and live or frozen brine shrimp and daphnia

Tank

Seriously Fish suggests a 45 x 30cm base. Dense planting and floating plants to soften the light help it settle, and a lid is advisable because it jumps.

Water Temperature & Quality

Seriously Fish gives 21-28C, pH 4.5-7.5 and 5-12 dGH, extending well into acidic water, while FishBase records pH 6.0, 5-12 dH and 25-30C in the wild. Soft, slightly acidic water, for example over peat, suits it well.

Tank Mates

Peaceful but timid and easily outcompeted, so it is unsuited to a general community. A species tank, fish of comparable size and disposition, or Caridina and Neocaridina shrimp are the better options.

Diet & Feeding

Its mouth is very small, so choose the finest dried foods. Live or frozen brine shrimp and daphnia improve colour and breeding condition. Feed small amounts several times a day.

Breeding & Spawning

An egg scatterer with no parental care that eats its own eggs and fry. Spawning is more likely towards the upper end of the temperature range, the female attaching a few eggs daily over several days. Moving the eggs to a separate container raises survival.

Health & Notes

Peaceful but timid, and it will go hungry alongside faster fish. Groups of eight to ten or more settle it and bring out male display. It reacts badly to sudden changes in chemistry, so make small, frequent water changes in a small tank. The IUCN rates it Least Concern and it is not covered by CITES.

About Spotted Blue-eye

Pseudomugil gertrudae, the Spotted Blue-eye, is a tiny rainbowfish with a translucent body and yellow-edged fins. Max 3.8 cm, suited to intermediate keepers.

7 things to know before welcoming a Spotted Blue-eye

1. 1Small Size, Careful Volume

   Adults reach only about 3.8 cm, but this species naturally schools. Rather than keeping just one or two, aim for enough tank volume to house a small group so you can observe its natural swimming behavior.

2. 2A Timid Temperament

   This fish tends to be shy, so providing plants or other cover where it can retreat helps it settle in. A calm, secure environment brings out its natural coloration and behavior more readily.

3. 3Choosing Tankmates Carefully

   Because of its timid nature, this species does best in a single-species tank or alongside only very calm, small fish. Housing it with more active or larger fish can cause it to become stressed and withdrawn.

4. 4Watching Male Displays

   Males display by spreading their fins wide. Keeping several individuals in a calm setting gives you the chance to observe this courtship-like behavior.

5. 5Suited to Intermediate Keepers

   This species is generally considered suitable for intermediate keepers. It can be sensitive to sudden changes in water quality or environment, so maintaining stability is important.

6. 6Preparing the Tank in Advance

   Given its shy, delicate nature, setting up hiding spots and a calm layout before bringing the fish home can help it adjust more smoothly to its new environment.

7. 7What to Watch Day to Day

   With its translucent body, black spots, and yellow-edged fins, this species has a distinctive look that makes it easier to notice changes in coloration or fin condition during daily observation. Knowing its normal appearance is helpful.

Frequently asked questions about Spotted Blue-eye

Q.Can beginners keep the Spotted Blue-eye?

A.This species is classed as suitable for intermediate keepers. Its timid temperament and sensitivity to water quality changes make it better suited to those with some prior fishkeeping experience.

Q.Can it be kept with other fish?

A.Because it is timid, a single-species tank or pairing with only very calm, small fish works best. It can become withdrawn if kept with more active tankmates, so choose companions carefully.

Q.How large does it grow?

A.It is a very small species, reaching a maximum of only about 3.8 cm as an adult. Part of its appeal is watching it school in a group despite its diminutive size.

Q.How can males and females be told apart?

A.Males are known for spreading their fins wide in a display behavior. An individual showing this courtship-like posturing is likely to be male.

Q.Is this species subject to CITES regulations?

A.The Spotted Blue-eye is not subject to CITES.

Useful tools for Spotted Blue-eye care

Learn more about Spotted Blue-eye in the encyclopedia

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