Black Kumpay Goby (Stiphodon sp.)

Choose the Black Kumpay Goby for a clear, flowing stream tank

The Black Kumpay Goby, also sold as the Kumpay Black Goby, is a dark form of Stiphodon, a genus of small freshwater gobies from fast, clear streams on tropical islands. These are not the stout, sit-and-wait gobies of muddy estuaries. A Stiphodon is slim and lively, clings to rocks in strong current with a sucker disc formed from its joined pelvic fins, and spends the day grazing the thin film of algae and microorganisms that coats every stone.

"Black Kumpay" is a trade name rather than a scientific one, and the fish sold under it are not always named consistently. Some sellers label it Stiphodon atropurpureus. Seriously Fish notes that more than 30 Stiphodon species have been described, with a similar number awaiting description, that several look very alike and that many fish in the trade are mislabelled. We therefore sell it as Stiphodon sp. and base the care on the genus, which is the same for the dark forms.

Know what the names tell you

Browse our other Stiphodon stream gobies, such as the Blue Neon Goby and the Red Neon Sumatra Goby, the wider freshwater gobies and mudskippers range, or our bottom dwellers for more fish that live on the floor and the rocks.

Check what you receive

One purchase supplies one live Black Kumpay Goby in the standard size we stock. Stream gobies are normally wild-collected, so size, colour and pattern vary between fish, and the photographs show the type rather than the individual. The sex is not selected or guaranteed.

The sexes look different. In S. atropurpureus, Seriously Fish describes males as greyish with a bright blue to green stripe along the side, and females as much lighter with a dark, zig-zag stripe; as the trade name suggests, the fish sold as Black Kumpay are a dark form. Expect colours to be duller on arrival and to deepen once the fish settles, feeds well and starts to display.

Plan the group before you order

• Starter group: one male with two or more females, the minimum Seriously Fish recommends.
• More males: possible in a larger tank with plenty of stones and sight breaks, because males are only loosely territorial.
• One fish only: it will live alone, but you will see far more natural behaviour in a small group.

Because sex cannot be chosen, buying three or four gives the best chance of a mix. Check our delivery and Live Arrival Guarantee policy before ordering.

Plan the aquarium around the stream

The fish itself is small: Seriously Fish gives a maximum of 50 mm standard length, and FishBase gives 5.0 cm total length for S. atropurpureus. The tank needs to be sized for the habitat, not the fish. Seriously Fish recommends a base of at least 60 x 30 cm, about 54 litres, for a pair or small group, and a larger aquarium if you plan several males or more than one goby species. OATA's freshwater goby care sheet gives at least 40 litres for a group of the smallest gobies and adds that larger tanks are more stable.

A long, shallow tank suits these gobies better than a tall one: the action happens on the floor and on the stones, and a shallow tank is easier to keep well lit and well oxygenated. Our tank volume calculator converts your measurements into litres, and the nano tank fish range lists other small species that share similar set-ups.

Copy the wild habitat

Build the layout from smooth stones

Seriously Fish recommends a substrate of sand, gravel or a mix, covered with a layer of water-worn rocks and pebbles, with larger stones placed directly on the base glass so they cannot be undermined. Aged driftwood can be added; new wood leaches tannins that cloud the clear water these fish come from. Hardy plants such as Microsorum, Crinum and Anubias cope with the flow. OATA advises fine gravel or sand to protect a goby's sensitive skin.

Fit a tight lid. Seriously Fish warns that Stiphodon can climb the glass, which is how juveniles climb waterfalls in the wild, and OATA says gobies can jump when startled. Cover filter inlets with sponge so a small goby cannot be drawn in.

Divide the footprint by purpose

Our hillstream loach guide describes the same kind of river-tank layout, and many of its tips on flow and stones apply directly to Stiphodon.

Keep water cool, clean and full of oxygen

The two published sources aim at different fish. Seriously Fish gives values for this genus; OATA's sheet covers freshwater gobies as a group, including brackish species, so its pH and hardness run higher. Aim for the species values and keep them stable.

Oxygen matters as much as the numbers. Warm water holds less oxygen, so Seriously Fish asks for extra surface movement towards the top of the range. In a heatwave, add an airstone and keep the room cool rather than letting the tank drift above 26°C.

Match your tap water first

Many UK areas, especially in the south and east, supply hard, alkaline water above the species range. Test your tap water first. If it is very hard, mix it with reverse-osmosis or rainwater-quality water to bring the hardness down, and make every water change with the same mix. Our water chemistry guide explains how, and the water matcher compares your readings with this fish.

Run strong filtration and frequent water changes

Seriously Fish asks for clean, well-oxygenated water from an oversized filter, powerheads, flow pumps or airstones, and gives several turnover figures: 10 to 15 times the tank volume per hour in one place, 8 to 12 in another, and 5 to 10 if the water is otherwise well oxygenated. In practice, choose a filter rated well above your tank volume and add a powerhead to push water along the stones. Our guide to aquarium filtration explains turnover.

Seriously Fish recommends changing 30 to 50% of the water every week and says Stiphodon should not go into an immature tank. OATA's minimum for gobies is 25% a week; the higher figure suits these stream fish better.

Follow a weekly routine

1. Test ammonia, nitrite, nitrate, pH and temperature.
2. Change 30 to 50% of the water with dechlorinated water at the same temperature.
3. Leave the algae on the stones; clean only the front glass.
4. Rinse filter sponges in removed tank water when the flow drops, never under the tap.
5. Check that the lid and inlet guards are still in place.

Grow its food on the rocks

Stiphodon are specialised grazers. FishBase records that they feed mainly on epiphytes and biofilm on rocks in the wild, and Seriously Fish explains that their staple is algae-covered surfaces, ideally soft diatoms and green algae rather than tough black brush algae. Seriously Fish adds that sinking dried foods and small meaty foods such as bloodworm may be accepted but should be offered only now and then, and warns that wild-caught or poorly kept fish are often sold thin.

That means the tank must produce food. Bright lighting on the stones, a mature tank and a light hand with algae scraping keep a grazing film going. Seriously Fish also suggests an algae nursery: a separate container of stones kept in a bright spot, swapped into the tank as the stones in the aquarium are grazed clean. Our guide to aquarium algae explains which algae grow in which conditions.

Build one measured meal

• Every day: algae and biofilm on well-lit stones.
• A few times a week: a small piece of green algae wafers or a pinch of spirulina mini granules placed on a stone.
• Occasionally: a little frozen food such as daphnia or bloodworm.
• Quantity: OATA says feed only what is eaten within a few minutes; remove leftovers.

A well-fed Stiphodon has a gently rounded belly. A pinched, hollow belly means the tank is not producing enough algae for the number of grazers.

Introduce them calmly and watch the first week

Add the gobies only to a mature tank with algae already growing on the stones. OATA advises checking that ammonia and nitrite read zero first, adding fish slowly so the filter bacteria keep pace, and, for wild-caught fish, keeping lighting dim at first and quarantining new arrivals where possible. Our guide to acclimatising new fish covers the steps in detail.

Use OATA's floating-bag method

1. Switch off the aquarium lights.
2. Float the sealed bag for 10 minutes to match the temperature.
3. Add small amounts of aquarium water to the bag over up to 20 minutes.
4. Net the gobies into the aquarium, keeping the bag water out.
5. Leave the lights off for the rest of the day.

Choose calm, small tank mates

Stiphodon can live in a community if the companions are chosen carefully. Seriously Fish suggests Tanichthys, Microdevario, smaller danios, small characins and livebearers, and Caridina or Neocaridina shrimp for the upper levels, and small hillstream loaches such as Gastromyzon and Pseudogastromyzon on the bottom. Other stream gobies, including Sicyopus and Rhinogobius, also make good companions. It advises against aggressive feeders such as many Schistura loaches, and against most cichlids and territorial fish.

Screen each tank mate

Every grazer competes for the same film on the stones, so count shrimp, loaches and gobies together when you judge how much algae the tank can supply. Our tank mates tool helps you check a planned community. If you are setting up a grazing tank from scratch, the algae eaters range shows other fish that share the same food.

Watch the group and act on changes

Most problems with Stiphodon come from three things: too little algae, too little oxygen and an open lid. Check the gobies every day, ideally when the lights come on and they start grazing, and compare their bellies and colour with the day before.

Pair each sign with an action

Understand why breeding stays in the wild

Stiphodon breed in their home streams but have not been raised in aquaria: Seriously Fish says no one has yet raised the fry of any Stiphodon species. OATA says the same of freshwater gobies in general, because their fry wash out to sea in the wild and are unlikely to survive in a home aquarium. Buy these fish for their behaviour and colour, not to breed them.

Follow the life cycle

1. The female attaches up to 10,000 tiny eggs under a stone and the male guards them (Seriously Fish).
2. The larvae hatch and drift downstream to the sea.
3. They live at sea for 78 to 146 days, longer in cooler water.
4. Juveniles return and climb upstream, even over waterfalls, using their sucker disc.

Answer Black Kumpay Goby buying questions

What is a Black Kumpay Goby?

It is a trade name for a dark freshwater stream goby of the genus Stiphodon, a group of small gobies from fast, clear island streams in Asia and the Pacific. The name is also written Kumpay Black Goby. Some sellers label it Stiphodon atropurpureus, but Stiphodon species are hard to tell apart, so we sell it as Stiphodon sp.

How big does it grow?

Small. Seriously Fish gives 50 mm standard length (body without the tail) for Stiphodon atropurpureus and FishBase gives 5 cm total length. Plan for a fish of about 5 to 6 cm.

What size tank does it need?

An aquarium with a base of at least 60 x 30 cm, about 54 litres, for one male and a few females, as Seriously Fish recommends. Use a larger tank for more than one male or for a mixed stream community.

Is it an algae eater?

It grazes algae and the film of microorganisms that grows on rocks, and it needs that film to stay healthy. It is not a clean-up fish: plan to grow algae for it rather than buying it to remove algae.

Does it need strong water flow?

It needs very clean, oxygen-rich water with plenty of movement. Seriously Fish suggests a filter turnover of roughly 8 to 15 times the tank volume per hour, or less if powerheads and airstones keep the oxygen level high.

Can I keep more than one?

Yes. Males are loosely territorial, so the best start is one male with two or more females. Several males can live together in a larger tank with plenty of rocks and sight breaks.

Can I breed it at home?

Not realistically. Stiphodon larvae drift to the sea and live there for months before returning to fresh water, and no one has yet raised Stiphodon fry in an aquarium.

Does it get on with shrimp?

Yes. Seriously Fish lists Caridina and Neocaridina shrimp as suitable companions, and the goby grazes rather than hunts.

Consult the care references

• Seriously Fish: Stiphodon atropurpureus: Stiphodon atropurpureus profile used for the genus: range, stream habitat, 50 mm SL, 60 x 30 cm tank, flow and oxygen, lid, water values, algae and biofilm diet, tank mates, male territoriality, female pattern, amphidromous breeding and the note that many traded Stiphodon are mislabelled.
• FishBase: Stiphodon atropurpureus: Stiphodon atropurpureus: maximum 5.0 cm TL, clear-stream habitat, diet of epiphytes and biofilm on rocks, amphidromous life cycle and IUCN Least Concern.
• OATA: How to look after freshwater gobies and blennies: UK trade guidance for freshwater gobies: group water values, tank size for small and larger species, substrate, cover, lid, feeding, weekly maintenance and acclimatisation.
• OATA: How to look after wild-caught freshwater fish: UK trade guidance for wild-caught freshwater fish: quarantine, dim lighting, first foods and drip acclimatisation.
• Tropical Fish Co delivery policy: current dispatch days and Live Arrival Guarantee terms.