--- type: species title: "Peacock Gudgeon Care Guide: Tank Size, Diet & Breeding Tips" slug: "peacock-gudgeon" category: "freshwater" scientificName: "Tateurndina ocellicauda" subcategory: "Freshwater Oddball" lastUpdated: "2026-04-24" readingTime: 9 url: https://www.fishstores.org/species/peacock-gudgeon --- # Peacock Gudgeon Care Guide: Tank Size, Diet & Breeding Tips *Tateurndina ocellicauda* Learn how to care for the vibrant Peacock Gudgeon (Tateurndina ocellicauda). Expert tips on tank mates, water parameters, and breeding these colorful sleepers. The peacock gudgeon (*Tateurndina ocellicauda*) is one of the most colorful freshwater fish you can keep in a small tank without venturing into difficult, demanding species. Neon blue stripes, a sunset-orange belly, and a distinct black "eye spot" on the tail base sit on a body that rarely exceeds three inches. They come from a single river system in Papua New Guinea, they are not actually gobies despite the common name "peacock goby," and they are one of the few freshwater oddballs that breed reliably in the home aquarium with parental care so attentive it surprises first-time keepers. This guide covers everything from tank size and water parameters through cave spawning behavior and what to inspect at the local fish store before you buy. ## Species Overview Peacock gudgeons are members of the family Eleotridae — the sleeper goby family — which is closely related to true gobies (Gobiidae) but distinct from them. Sleepers lack the fused pelvic fins that true gobies use as a suction disc, and they tend to perch on plant leaves and cave ceilings rather than gluing themselves to glass. The "peacock goby" common name is a misnomer that has stuck in the trade for decades. Calling them a peacock gudgeon is more accurate, but most stores still label tanks with both names. | Field | Value | | ----------- | -------------------------------------------- | | Adult size | 3 in (7.5 cm) | | Lifespan | 4-5 years | | Min tank | 15 gallons | | Temperament | Peaceful, mildly territorial during spawning | | Difficulty | Beginner to Intermediate | | Diet | Micro-predator (carnivore-leaning omnivore) | > **Sister-species naming confusion** > > The "peacock goby" name is a holdover from the early aquarium trade that classified any small, cave-dwelling fish as a goby. *Tateurndina ocellicauda* is technically a sleeper goby — a member of Eleotridae, not Gobiidae — and lacks the pelvic-fin suction disc of true gobies. They behave goby-like (perching, hopping, defending caves) but if you are looking up scientific resources or stocking advice, search for "peacock gudgeon" rather than "peacock goby" to avoid mixed-up information from saltwater goby keepers. ### Origin: The Slow-Moving Streams of Papua New Guinea Peacock gudgeons come from the river systems of eastern Papua New Guinea, with most documented collection points along the slow-moving lowland streams and rainforest pools draining into the Solomon Sea. The native habitat is shaded by overhanging vegetation, the substrate is leaf litter and fine sand, and the water sits in the high 70s with a near-neutral pH. They are not whitewater fish — they evolved in still pools and gentle backwaters where they can perch motionless on plant stems and ambush passing invertebrates. Almost every peacock gudgeon in the trade today is captive-bred. Wild collection still happens, but breeders in Eastern Europe, Southeast Asia, and the United States produce enough captive stock that wild fish are no longer the default. Captive-bred fish are hardier, accept prepared foods more readily, and arrive at stores with fewer parasites. ### Appearance: Identifying the "Eye Spot" and Neon Blue/Red Patterning The base body color is a soft pearl-blue that intensifies under good lighting and dim ambient light. Vertical stripes of bright sky blue run from the gill plate down the flanks, broken by red-orange dots that concentrate along the lateral line. The dorsal and anal fins carry neon blue edging with a wash of red-orange in the membrane, and the caudal peduncle bears a clear black spot — the "ocellus" — that gives the species its name (*ocellicauda* means "eye-tailed"). The color saturation peaks during display and spawning. A male defending a cave will flare his fins, intensify his red belly, and show his nuchal hump in full profile. Newly purchased fish in store tanks usually appear washed-out from shipping stress; expect 2 to 4 weeks before they fully color up in your tank. ### Sexual Dimorphism: Male Nuchal Hump vs. Female Yellow Belly Sexing peacock gudgeons is one of the easier identification jobs in the freshwater hobby once the fish are mature. Males develop a pronounced nuchal hump — a fleshy bulge on the forehead just behind the eyes — that gets more dramatic with age and during spawning. They are also slightly larger and more elongated, with longer dorsal and anal fins. Females are slightly smaller, more streamlined, and lack the nuchal hump entirely. The most reliable sex indicator on a female is a thin yellow or gold edge running along the bottom of the belly and onto the anal fin. Combined with the rounder, egg-laden body shape during conditioning, the yellow belly stripe makes adult females easy to pick out at the store. Juveniles under 2 inches are difficult to sex visually — buy a group of 4 to 6 if you want to guarantee getting a pair. ## Water Parameters & Tank Requirements Peacock gudgeons are flexible enough for most stable community tanks, but they color up best and breed most reliably when the setup mirrors their native lowland-stream habitat: warm, soft, slightly acidic to neutral water with plenty of cover and minimal current. ### Tank Size: Why 15 Gallons Is the Sweet Spot for a Pair A 15-gallon tank is the realistic minimum for a pair. Smaller tanks (10 gallons and under) physically fit the fish but do not give a male enough territory to claim a cave without harassing his mate, and they do not give the female enough open space to retreat when the male is in display mode. A 20-gallon long is the more comfortable choice for a pair plus a small group of dither fish, and it gives you room to add a second female if you want a one-male, two-female trio. If you are looking for a turnkey first tank that suits a peacock gudgeon pair, a [20-gallon fish tank](/guides/20-gallon-fish-tank) with a footprint of 24 by 12 inches gives the male enough territory to claim one end while the female holds the other. Floor space matters more than gallon volume for this species — they spend most of their time perched in the lower third of the tank. > **Peaceful enough for a nano community** > > Peacock gudgeons are one of the few "showpiece" nano fish that can genuinely cohabitate with a small group of peaceful tank mates without nipping or harassment. They ignore mid-water schoolers, perch among plants rather than chasing them, and only get territorial during active spawning. A pair of peacock gudgeons plus a small school of harlequin rasboras or chili rasboras in a planted 20-gallon is one of the most visually striking nano community setups available in the freshwater hobby. ### Ideal Parameters: Maintaining 72-79°F, pH 6.5-7.5 Target water parameters for a long-term peacock gudgeon tank: - **Temperature:** 72-79 F (22-26 C). Stable at the middle of the range is better than oscillating across it. - **pH:** 6.5-7.5. Wild fish were collected from water close to neutral; captive-bred stock tolerates the full range. - **Hardness:** 5-12 dGH. Soft to moderately hard. They are not as sensitive to hardness as some blackwater species. - **Ammonia / Nitrite:** 0 ppm. Non-negotiable. - **Nitrate:** Under 20 ppm with weekly water changes. Peacock gudgeons are sensitive to nitrate creep in under-maintained tanks. A tank that runs at 40-60 ppm nitrate for weeks will produce washed-out, lethargic fish with poor breeding response. Weekly 25-30% water changes are the cleanest way to keep nitrate in check and trigger natural color and breeding behavior. ### Aquascaping: PVC Pipes, Caves, and Dense Vegetation The aquascape does most of the work in a peacock gudgeon tank. The two non-negotiable elements are caves and plants. Provide at least one cave per male in the tank. A short length of black PVC pipe (1 inch diameter, 3 inches long) is the budget-friendly option that males consistently prefer for spawning. Coconut shell caves, ceramic shrimp caves, and stacked rock structures all work too. Caves should sit on the substrate, have a single entrance roughly the diameter of the male's body, and be located in a quieter corner of the tank away from high-flow areas. Plant density matters as much as cave count. Java fern attached to driftwood, anubias on rockwork, cryptocoryne species in the substrate, and floating plants like amazon frogbit or water lettuce all work well. Floating plants are particularly important because they dim the surface light and make the gudgeons feel secure enough to come out and display. A bright, sparsely planted tank produces fish that hide constantly — dense planting is what unlocks the behavior people buy them for. > **Dim lighting plus caves equals fish you actually see** > > Peacock gudgeons evolved under shaded jungle canopy and behave dramatically differently in dim, planted tanks versus brightly lit show tanks. Cut surface light with floating plants (amazon frogbit, water lettuce, red root floaters) and provide enough caves that each fish has its own retreat. The counter-intuitive result: dim, cave-heavy tanks produce fish that spend more time visible in the open water column because they trust they have somewhere to retreat. Bright, sparse tanks produce fish that hide constantly behind whatever sliver of cover they can find. ## Diet & Feeding Peacock gudgeons are micro-predators in the wild. They eat small invertebrates, insect larvae, and occasional small fish fry that drift through their territory. In captivity they are not picky eaters once they settle in, but they have a strong preference for moving food and meaty items over flake. ### Overcoming Picky Eating: Transitioning from Frozen to Pellets Newly purchased peacock gudgeons often refuse dry food for the first 1 to 2 weeks. Most stores condition them on frozen bloodworms or live foods, and the switch to a flake or pellet routine takes patience. The standard transition strategy is to start with frozen foods that the fish will eat reliably, then mix in a small amount of high-quality sinking pellet alongside the frozen item. Over 2 to 4 weeks, gradually shift the ratio toward pellets while reducing the frozen portion. A high-protein sinking pellet (Hikari Vibra Bites, Bug Bites Pleco/Catfish formula in small sizes, or NLS small fish formula) is the daily staple goal. Flake food works in a pinch but tends to float, and peacock gudgeons feed mostly in the lower water column off the substrate or plant surfaces. ### Best Foods: Bloodworms, Brine Shrimp, and Daphnia Live and frozen foods bring out the best color and behavior. Frozen bloodworms are the gold standard — peacock gudgeons go after them aggressively, and a few cubes per week dramatically intensify red and orange coloration. Frozen brine shrimp, mysis shrimp, and daphnia rotate well as alternatives. Live foods (blackworms, chopped earthworms, mosquito larvae in season) are even more effective at triggering breeding behavior, but they are not necessary for general health. Feed once or twice per day, small amounts each time. A pair of peacock gudgeons will eat a half-cube of frozen bloodworms in a single sitting; anything larger leaves uneaten food on the substrate that fouls a small tank quickly. ## Tank Mates & Compatibility Peacock gudgeons are peaceful toward unrelated species and only territorial toward their own kind during spawning. The tank mate selection problem is more about avoiding fish that will harass them than fish they will harass. ### Top Community Picks The best tank mates are peaceful, mid-water dither fish that occupy a different niche from the bottom-perching gudgeons. [Celestial pearl danios](/species/celestial-pearl-danio), harlequin rasboras, ember tetras, chili rasboras, and small pencilfish all work well. Honey gouramis are an excellent surface-level companion that stays out of the gudgeons' cave territory. Pygmy corydoras and other small corys make good substrate companions because they ignore the gudgeons entirely and feed on different food sources. For a slightly larger community in a 30-gallon plus, sparkling gouramis, kuhli loaches, and a small school of rummy nose tetras all coexist peacefully with a peacock gudgeon pair. ### Invertebrate Warning: Risk Levels with Cherry Shrimp and Snails Peacock gudgeons are micro-predators and will eat small invertebrates. Adult Neocaridina shrimp (cherry, blue dream, sakura) are usually too large to be eaten outright, but shrimplets are fair game and will be picked off as the gudgeons find them. A heavily planted tank with thick moss and crevices can sustain a shrimp colony alongside a gudgeon pair, but expect attrition rather than population growth. Snails are mostly safe — nerite, mystery, and rabbit snails are too large and hard-shelled to be bothered. Small ramshorn or bladder snails may get picked at occasionally but the gudgeons will not actively hunt them. ### Species to Avoid Avoid keeping with aggressive fish, fast competitive feeders, or fin nippers. Tiger barbs, larger barbs, and most cichlids over 4 inches will out-compete the gudgeons at feeding time and stress them off their caves. Avoid bettas — peacock gudgeons spend time near the surface and at mid-column, where a territorial male betta will harass them constantly. Larger predatory fish (angelfish, larger gouramis like opaline or pearl) view juvenile gudgeons as prey items and should not share a tank with them. For other compatible peaceful nano oddballs, the [scarlet badis](/species/scarlet-badis) and [dwarf pea puffer](/species/dwarf-pea-puffer) are sometimes suggested, but both are themselves territorial enough that combining them with peacock gudgeons in anything under a 30-gallon tank usually goes badly. Keep one cave-spawning species per nano tank. ## Breeding the Peacock Gudgeon Peacock gudgeons are one of the most rewarding freshwater species to breed in the home aquarium. They spawn readily once paired, and the male provides genuine parental care — guarding and fanning the eggs from spawning through hatch. ### Triggering Spawning: Condition with Live Foods and Water Changes A bonded pair in a stable tank will often spawn without any deliberate trigger, but the standard breeding-conditioning trick reliably accelerates the process. Feed live or frozen foods (bloodworms, blackworms, daphnia, brine shrimp) two to three times daily for 1 to 2 weeks. The female fills with eggs and her belly rounds out visibly. The male intensifies his color and starts defending a cave aggressively. A larger-than-usual water change (40-50%) with slightly cooler water (drop 2-3 F) often triggers spawning within 24 to 72 hours. This mimics a rainy-season water influx in their native habitat and is the most consistent breeding trigger for the species. > **Breeding pairs are great parents — males guard the eggs** > > Unlike most egg-scattering nano fish where you have to remove the parents to save the spawn, peacock gudgeon males are dedicated parents. After spawning, the male takes over the cave entirely, fans water across the eggs with his pectoral fins for oxygenation, and chases off anything that approaches — including the female. He stays on the eggs for the full 7 to 10 day incubation without eating. This natural parental behavior means you can leave the pair in the community tank during incubation and let nature handle the rearing, which is one of the most enjoyable behaviors to watch in the entire freshwater hobby. ### Cave Spawning Behavior The female enters the male's chosen cave and deposits 50 to 100 eggs on the cave ceiling in a tight cluster. The male fertilizes them, then drives the female out and takes sole possession of the cave for the duration of incubation. He fans water across the eggs constantly, picks out any unfertilized or fungused eggs, and aggressively defends the cave entrance. The male will not eat during this period and will lose noticeable body condition by hatch — feed him heavily for 1 to 2 weeks after the fry are free-swimming to recover his weight. Eggs hatch in 7 to 10 days at 78 F. Fry are tiny — about 4 mm — and remain in the cave for an additional 2 to 3 days absorbing their yolk sac before swimming out into the tank. ### Raising Fry: Infusoria and Baby Brine Shrimp Free-swimming peacock gudgeon fry are too small to eat newly hatched baby brine shrimp for the first 5 to 7 days. They need infusoria, vinegar eels, or commercial liquid fry food sized for nano-fish fry as the starter food. Around day 7 to 10, transition to freshly hatched baby brine shrimp, which they will hunt aggressively. In a community tank, fry survival is low — adult tank mates and even the parents will pick off small fry once they leave the cave. For serious breeding, transfer the male and his cave to a separate 5 to 10 gallon rearing tank a few days before hatch and let him guard the fry through their first week. After they are free-swimming and feeding on infusoria, return him to the main tank and raise the fry separately. ## Common Health Issues Peacock gudgeons are generally hardy once acclimated, but their cave-dwelling lifestyle and small size make them vulnerable to a few specific issues. ### Fungal Infections: Treating "Cotton Wool" Disease Cotton wool disease (Saprolegnia infection) presents as fluffy, white, cotton-like growths on the body, fins, or eggs. It is opportunistic — it follows physical damage, poor water quality, or stress, and it appears more often in cave-dwelling species because cave injuries from cramped territories and squabbles over spawning spots are common. Treatment in a quarantine tank with methylene blue or a broad-spectrum antifungal (such as Pimafix or API Fungus Cure) at half-dose works well for early-stage infections. Address the underlying cause first: check water parameters, look for aggression from cave-mates, and add more caves so individual fish are not being driven into territorial conflicts. ### Internal Parasites: Sunken Bellies and Stringy White Poop Internal parasites are the most common death mechanism for newly imported peacock gudgeons. Symptoms include hollow or sunken bellies despite eating, stringy white feces, gradual weight loss, and lethargy. Captive-bred stock from established farms is much less prone to this than wild-caught fish. Treatment requires medicated food. Soak high-quality pellets in a fenbendazole or praziquantel solution and feed for 5 to 7 days. Levamisole-medicated foods work as a backup. Quarantine all new peacock gudgeons for 3 to 4 weeks before adding to a display tank, and consider a prophylactic round of medicated food during quarantine if the fish came from an unknown source. The [acclimation guide](/guides/how-to-acclimate-fish) covers the slow drip method that minimizes stress on imports. ## Where to Buy & What to Look For Peacock gudgeons are widely available in the freshwater trade but vary enormously in quality between sources. The healthiest fish come from local fish stores that source from reputable captive-bred suppliers and quarantine new arrivals before putting them on the sales floor. > **Buy Local** > > Inspect peacock gudgeons in person before buying. Look for active perching behavior on caves, plants, or substrate (not hanging at the surface or hiding constantly), full body coloration without faded patches, intact fins with no white edging, and no sign of clamped fins which is the most common stress indicator for this species during transport. Avoid stores where the gudgeon tank shows visibly thin or sunken-bellied fish — internal parasites are common in poorly sourced stock. ### LFS Inspection: Active Swimming and Vibrant Fin Coloration When you walk up to the tank, healthy peacock gudgeons should react to your presence — perched fish should turn to look at you, and males should briefly flare fins if they feel territorial pressure. Fish that ignore you, hang motionless near the surface, or show clamped (folded-against-body) dorsal and anal fins are stressed or sick. Walk away from tanks where multiple fish show those symptoms. Specific things to check before purchase: - **Body condition:** No sunken belly. The flank just behind the gill plate should be smooth and rounded, not concave. - **Fin condition:** Dorsal and anal fins fully extended at rest, no fraying, no white edges (early fin rot). - **Coloration:** Visible blue stripes and red-orange belly. Fully washed-out gray fish are stressed and may be sick. - **Eyes:** Clear, no cloudiness, no pop-eye. - **Behavior:** Active perching, occasional swimming, normal feeding response when food is offered. - **Sex:** If you want a guaranteed pair, look for one fish with a clear nuchal hump (male) and one with a yellow belly stripe (female). ### Acclimation Peacock gudgeons handle the standard drip acclimation method well. Float the bag for 15 minutes to equalize temperature, then drip tank water into the bag at a rate of 2 to 3 drops per second for 45 to 60 minutes. Net the fish out into the tank rather than pouring bag water into your display. Give the new fish 24 to 48 hours of low-stress observation before feeding heavily — initial refusal to eat is normal and not cause for concern. For broader context on selecting and stocking nano oddballs, the [freshwater fish guide](/guides/freshwater-fish) covers the cycling and tank prep that should happen before any livestock goes in. ## Quick Reference - **Tank size:** 15 gallons minimum (20 gallon long preferred for a pair plus dithers) - **Temperature:** 72-79 F (22-26 C) - **pH:** 6.5-7.5 (near-neutral preferred) - **Hardness:** 5-12 dGH (soft to moderately hard) - **Ammonia / Nitrite:** 0 ppm - **Nitrate:** Under 20 ppm - **Adult size:** 3 in (7.5 cm); males slightly larger with nuchal hump - **Lifespan:** 4-5 years - **Diet:** Micro-predator — frozen bloodworms, brine shrimp, daphnia, sinking high-protein pellets - **Filtration:** Sponge filter or baffled HOB; gentle flow only - **Lighting:** Dim to moderate; floating plants reduce surface intensity - **Aquascape:** PVC or coconut caves (1 per male), dense planting, leaf litter optional - **Group size:** Pair (1M / 1F) or trio (1M / 2F); avoid multiple males in tanks under 30 gallons - **Best tank mates:** [Celestial pearl danios](/species/celestial-pearl-danio), harlequin rasboras, honey gouramis, pygmy corydoras, kuhli loaches - **Avoid:** Bettas, larger gouramis, fin-nippers, multiple males in small tanks - **Breeding:** Cave spawner; male guards eggs for 7-10 days; condition with live foods and cool water change - **Difficulty:** Beginner to Intermediate - **Lid required:** Yes — peacock gudgeons can leap from open-top tanks if startled For a complete starter setup that suits a peacock gudgeon pair, see the [20-gallon fish tank guide](/guides/20-gallon-fish-tank). The same dim-lighting, dense-planting, cave-heavy aquascape principles apply to most freshwater oddball species — for a broader look at how peacock gudgeons fit alongside other nano-friendly options, the [freshwater fish guide](/guides/freshwater-fish) covers complementary species and stocking strategy. ## Frequently Asked Questions ### How big do peacock gudgeons get? Peacock gudgeons are small, typically reaching a maximum size of 2.5 to 3 inches. Males are generally slightly larger and develop a more pronounced, rounded forehead (nuchal hump) as they mature, while females remain smaller with a more streamlined profile. ### Are peacock gudgeons aggressive? They are generally peaceful community fish but can be territorial toward their own kind, especially during spawning. In a tank smaller than 15 gallons, males may bicker over caves. Providing multiple hiding spots ensures a peaceful environment for all inhabitants. ### Do peacock gudgeons need a lid? Yes, a tight-fitting lid is essential. While not known as "high jumpers" like Hatchetfish, Peacock Gudgeons are curious and can easily leap out of an open-top aquarium if startled or during a chase. ### Can peacock gudgeons live with shrimp? It is a risk. While they are small, they are micro-predators. They will almost certainly eat shrimplets and may harass adult Neocaridina. If you keep them together, ensure the tank is heavily planted with plenty of moss for shrimp safety. ### How many peacock gudgeons should be kept together? They do best in pairs (one male, one female) or small groups (one male to two or three females). Keeping multiple males in a small tank can lead to aggression unless the footprint is large enough to establish separate territories. --- *Source: [FishStores.org](https://www.fishstores.org/species/peacock-gudgeon)* *Last updated: April 24, 2026*