Peacock Gudgeon Care Guide

The peacock gudgeon is one of the best-behaved nano centrepieces in the hobby - a stunning, peaceful, cave-spawning sleeper around 7.5 cm long. It is not, though, the pet-rock the trade name suggests: it is a micropredator that wants small live and frozen food to colour up, a confirmed jumper that needs a tight lid, and a fish that will pick off dwarf-shrimp fry, so it is no guardian for a breeding shrimp colony. Despite the "peacock goby" label it is an eleotrid sleeper, Tateurndina ocellicauda, not a true goby at all.

Peacock Gudgeon at a glance

The sourced figures the welfare engine uses to judge Peacock Gudgeon — the parseable key facts.

Where it comes from

It is endemic to the lowland rivers, streams and ponds of eastern Papua New Guinea, where FishBase records it forming schools that hover over the bottom in rainforest streams over soft substrate, leaf litter and bogwood among dense planting. Every care choice falls out of that biotope. The still, shaded rainforest pools mean low-to-moderate flow and a heavily planted, broken-up tank - in a sparse, bright tank the fish stays shy, while a decorated one brings it out and about much more often. The bottom-hovering sleeper habit means it wants visual cover and territory near the substrate, with sand or fine substrate and bogwood. The micro-invertebrate-rich water means a micropredator's diet, not a flake specialist's, and the warm tropical origin means a community-warm tank around 24 C, never coldwater.

Did you know?

• Its name is literal: ocellicauda means 'eye-spotted tail', after the dark ocellus (false eye) at the base of the tail - a classic predator-deflection marking.
• It is a sleeper, not a goby - an eleotrid with no fused pelvic-fin sucker, despite the 'peacock goby' trade name.
• Single-dad care: the male alone guards and fans the eggs in the cave until they hatch, while the female leaves after spawning.
• Dominant breeding males grow a pronounced nuchal hump on the forehead - a living rank badge.
• It is assessed by the IUCN as Vulnerable, with medium resilience and a population doubling time of 1.4 to 4.4 years - a reason to choose tank-bred stock.

Tank size — and why

A pair is comfortable in around 10-15 US gallons - Seriously Fish gives an 18 by 12 by 12 inch (45 by 30 by 30 cm) tank of about 40 litres as adequate for two adult pairs, and Fish Laboratory suggests 15 gallons for a small group. The driver is footprint, caves and sightline breaks rather than volume: this is a small, territory-aware bottom-hugger, and males need cover and broken lines of sight to hold their little patches without constant friction. Plan the layout around the floor and the hardscape, not the height.

As a guide, a 20-gallon tank comfortably suits about 2 Peacock Gudgeon as a single-species display, leaving room for tankmates.

How big does it really get?

Full-grown Peacock Gudgeon reach about 7.5 cm (3 in) long, but they are usually sold at only about 2.5 cm (1 in) — a typical shop size (estimate). At full size, Peacock Gudgeon needs roughly a 15-gallon tank, about 51 cm long; a common 10-gallon starter kit is only about 51 cm.

Adult size is sourced; the shop size is a typical-juvenile estimate; tank length is approximate for a standard 15-gallon aquarium.

Water parameters in practice

Keep it warm and stable at 22-26 C, near-neutral at pH 6.5-7.5 (it tolerates roughly 6.0-7.8), and in soft to moderately hard water, around 5-12 degrees. The point every source hammers is that stability beats hitting an exact number - temperature swings, not a precise reading, are what invite trouble. It is not delicate on parameters, but it does prefer clean, soft-neutral water, so keep ammonia and nitrite at zero and do regular small changes. It is a low-bioload fish, so standard nano filtration and weekly changes are plenty.

Diet & feeding

In the wild it is a micropredator and suction feeder taking insects, insect larvae and small crustaceans, and that habit carries straight into the tank. It strongly prefers small live and frozen foods - bloodworm, daphnia, brine shrimp, cyclops, mysis and micro-worms - and while it will accept dried food, it colours up far better on live and frozen fare, so dry food alone is a mistake. Feed small daily portions, and watch that it actually gets fed: it is a deliberate, sometimes shy feeder that can be out-competed by faster fish, so make sure food reaches it. The load-bearing caveat is at the bottom of the food chain - as a micropredator it eats small aquarium pests and will prey on dwarf-shrimp fry and the smallest newborn shrimp.

Gear & setup

Set it up with a soft, fine substrate, dense planting (Anubias, Java fern, Cryptocoryne), bogwood, and caves or crevices that double as security and as spawning sites - a well-decorated tank makes the fish bolder and constantly visible. Keep flow low to moderate to mimic slow rainforest pools. The non-negotiable piece of kit is a tight-fitting lid: peacock gudgeons are very adept jumpers, and an open top is one of the most common avoidable causes of death. Standard nano filtration suits its low bioload.

Temperament & behaviour

It is a genuinely peaceful community fish, suitable for calm nano communities, and only a little territorial with its own kind. Males spar and display - a pectoral-fin play-fighting that looks dramatic but rarely causes injury - and hold small territories, so multiple males want space, caves and sightline breaks. The other defining trait is boldness as a function of decor: shy and hidden in a bare, bright tank, but bold and out front in a densely planted, shaded one with gentle tankmates.

Group & social needs

Keep it as a bonded pair or a small group - a pair is the practical minimum, with small groups of six to eight working well in a larger tank. It is not an obligate tight schooler in captivity, though wild fish form loose shoals that hover over the bottom. Males will spar and hold small territories, so give several males room and broken sightlines; the cost of crowding is stress and display, rarely real harm.

Compatible tank mates (preview)

A short, engine-cleared shortlist — the species TankStocking's welfare engine clears with Peacock Gudgeon and that suit its size and temperament best. Tap any to load the pairing in the planner.

• Amano Shrimp — Peaceful temperament, similar adult size.
• Bamboo Shrimp (Wood/Fan Shrimp) — Peaceful temperament, similar adult size.
• Boesemani Rainbowfish — Peaceful temperament, similar adult size.

A note on the shrimp and snails here: Peacock Gudgeon is peaceful and generally invertebrate-safe — but almost any fish will take very small shrimplets given the chance, so give shrimp dense cover (moss, leaf litter) if you want a colony to grow, rather than expecting every baby to survive.

This engine-cleared shortlist is Peacock Gudgeon's tankmate surface for now — a dedicated tank-mates guide can follow for high-demand species.

Breeding & sexing

Breeding is easy to moderate and a delight to watch - the main work is conditioning on live food and raising the tiny fry. Sexing is reliable: males are larger and brighter and develop a pronounced nuchal (forehead) hump, while females stay smaller, show a yellow belly and carry a distinctive dark bar along the edge of the anal fin that males lack. It is a cave spawner: a pair selects and cleans a crevice, cave or spawning tube, and the female attaches roughly 30 to 100 eggs by small adhesive threads. The male alone then guards and fans the eggs - the female leaves - with hatch timing reported from a day or two up to several days. The fry are tiny and slow-growing, needing infusoria, microworms or green water before they can take baby brine shrimp, and reach maturity at around six to eight months.

Lifespan

Typically about 4-5 years in good conditions. What shortens it: starvation or poor diet, since a picky micropredator fades on dry-only food; bullying or out-competition by larger, boisterous tankmates that stress it into hiding and not feeding; jumping out of an open-top tank, a genuinely common loss; and poor water quality or unstable temperature, which invites ich and other stress disease.

Common mistakes

• Expecting it to thrive on flakes. It is a micropredator - feed small live or frozen foods or it slowly fades; dry food alone is not enough.
• Running an open-top tank. Peacock gudgeons are very adept jumpers, and a missing or loose lid is one of the most common killers.
• Pairing it with boisterous, fast or greedy feeders. The deliberate, shy gudgeon gets out-competed at feeding and stressed into hiding.
• Relying on it as a shrimp-colony tankmate. It eats dwarf-shrimp fry and the smallest shrimp, so it is not safe for a fry-producing cherry or neocaridina colony, even though adult larger shrimp generally co-exist.
• A sparse, bright tank. Without dense planting, caves and shade it stays chronically shy and rarely shows its colours.
• Cool or unstable water. Temperature swings invite ich; keep it warm and steady rather than chasing an exact figure.

Signs of trouble

• Paleness and faded colour - early stress, often from a bare tank, bold tankmates or unstable water.
• Hiding and refusing food - stress or out-competition; check whether faster tankmates are intercepting the food.
• A thin or pinched belly - under-feeding, common when it is kept on dry food or with greedy feeders.
• Clamped fins and sitting in cover - general stress or early illness; check temperature stability first.
• White spots with flashing - ich, usually triggered by a temperature swing.

Is this fish right for you?

Do not buy a peacock gudgeon if you won't provide small live or frozen foods - it is a micropredator and slowly declines on dry food alone. Do not buy one for an open-top tank: it is a very adept jumper and a tight lid is mandatory. Do not buy it as a guardian for a breeding dwarf-shrimp colony, because it eats shrimp fry and the smallest shrimplets, and do not house it with boisterous, fast or large fish that will out-compete it at feeding or simply eat a 7.5 cm sleeper. On stock, it is generally tank-bred and robust, but the species is assessed by the IUCN as Vulnerable with only medium resilience, so favour tank-bred fish, choose active well-coloured individuals, and quarantine as standard.

Common questions

Are peacock gudgeons peaceful and good in a community?

Yes - they are genuinely peaceful and one of the best nano-community centrepieces, only a little territorial with their own kind. The catch is the other direction: keep them with calm, non-pushy fish, because boisterous fast feeders out-compete and stress them, and large fish will eat a 7.5 cm sleeper.

Do peacock gudgeons jump?

Yes - they are very adept jumpers, and an open top is one of the most common avoidable causes of death. A tight-fitting lid is mandatory, not optional.

Are peacock gudgeons shrimp-safe?

Partly. Adults of larger shrimp such as Amano generally co-exist, but as a micropredator the gudgeon eats dwarf-shrimp fry and the smallest shrimp, so it is not safe for a breeding cherry or neocaridina colony.

What do peacock gudgeons eat - will they take flakes?

They are micropredators that strongly prefer small live and frozen foods like bloodworm, daphnia and brine shrimp. They will accept dried food, but colour up far better on live and frozen fare, so don't rely on flakes alone.

How many peacock gudgeons should I keep, and how do I sex them?

Keep a bonded pair at minimum, or a small group of six to eight in a larger, well-planted tank with caves. Males are larger and brighter with a forehead (nuchal) hump; females are smaller with a yellow belly and a dark bar along the anal-fin edge.

What size tank does a peacock gudgeon need?

About 10-15 US gallons for a pair or small group. Footprint, caves and sightline breaks matter more than volume, so males can hold small territories without constant friction.

Sources & confidence

Sources & confidence (9 species)

These back the Peacock Gudgeon figures and the previewed tank mates above. Each figure is read from the TankStocking species database (v2026.06); below is the care reference behind it and how confident we are in that data. Confidence reflects the source quality, not whether any pairing is safe. Full source list and the welfare model are on the methodology page.

• Peacock Gudgeon Tateurndina ocellicauda — Seriously Fish (seriouslyfish.com/species/tateurndina-ocellicauda) high confidence
• Amano Shrimp Caridina multidentata — Aquarium Co-Op amano shrimp care; Aquadiction high confidence
• Bamboo Shrimp (Wood/Fan Shrimp) Atyopsis moluccensis — Aquariadise (aquariadise.com/caresheet-bamboo-shrimp-atyopsis-moluccensis) high confidence
• Boesemani Rainbowfish Melanotaenia boesemani — Seriously Fish; Aquarium Co-Op Boesemani guide high confidence
• Bolivian Ram Mikrogeophagus altispinosus — Seriously Fish (seriouslyfish.com/species/mikrogeophagus-altispinosus) high confidence
• Brilliant Rasbora Rasbora einthovenii — Seriously Fish (seriouslyfish.com/species/rasbora-einthovenii) high confidence
• Bristlenose Pleco Ancistrus sp. — Aquarium Source / aqua-fish.net Ancistrus care guides high confidence
• Bronze Corydoras Corydoras aeneus — Seriously Fish (seriouslyfish.com/species/corydoras-aeneus) high confidence
• Checker Barb Oliotius oligolepis — Seriously Fish — Oliotius oligolepis (https://www.seriouslyfish.com/species/oliotius-oligolepis/) high confidence

Care-guide sources (6)

This guide synthesises the references below; where they disagree, the range and the disagreement are noted in the text above. The figures in the key-facts box are read from the TankStocking species database (v2026.06). Full welfare model on the methodology page.

• FishBase - Tateurndina ocellicauda — authority (Nichols, 1955), Eleotridae, 7.5 cm TL, eastern Papua New Guinea, demersal, 'Forms schools that hover over the bottom', 22-26 C / pH up to ~7.0 / dH up to ~7, trophic 3.2, ~30 eggs with male guarding and fanning, hatch ~6 days, IUCN Vulnerable, medium resilience
• Seriously Fish - Tateurndina ocellicauda — 7.5 cm SL, PNG lowlands, loose shoals, 45x30x30 cm / ~40 L for two pairs, 22-26 C / pH 6.5-7.5 / 5-10 H, prefers 'small live and frozen stuff...bloodworm, daphnia, brineshrimp', 'a little territorial with its own kind', 'not actually a goby...Eleotridae', cave spawning, male brood care, sexing (yellow belly, anal-fin bar)
• Wikipedia - Peacock gudgeon — Nichols 1955, Eleotridae 'not gobies', endemic PNG, IUCN Vulnerable, males 7.5 cm with nuchal hump / females ~5 cm with yellow belly and black anal-fin bar, cave spawner 50-100 eggs, male fans 8-10 days, maturity 6-8 months, diet 'insects, insect larvae, and small crustaceans'
• Fish Laboratory - Peacock Gudgeon Ultimate Care Guide — 4-5 yr lifespan, 15 gal group, 72-79 F (stable), pH 6-7.8 / 5-12 dKH, 'highly picky...prefer live foods', tankmate lists, males 'play-fight but rarely cause injury', 'very adept jumpers' - tight lid, cave spawning 50-100 eggs, ich / hole-in-head / dropsy
• aqua-fish.net - Peacock Gudgeon care — corroborates 22-26 C, low flow, picky live/frozen feeding, dwarf-shrimp-fry predation ('may prey on dwarf shrimp...especially their fry'), pair / small-group keeping
• Aquadiction / Shrimpy Business / Aquarium Source - Peacock Gudgeon profiles — corroborate 4-5 yr lifespan, peaceful nano-community tankmates, live/frozen diet, and the shrimp-fry vs large-shrimp compatibility nuance

More on Peacock Gudgeon

Related guides on TankStocking — each scored by the same welfare engine as the planner.

This care guide is a sourced planning reference, not veterinary advice — individual fish, filtration and maintenance all matter. Cycle the tank, test your water, and observe your fish. How TankStocking works →