A peaceful, nocturnal spiny eel native to Southeast Asia, easily identified by the false eyespots (ocelli) along its dorsal fin. They are notorious escape artists and avid burrowers. A soft sand substrate is absolutely mandatory to prevent severe bacterial skin infections from scratching, along with a tight-fitting lid. They are picky eaters that generally require live or frozen meaty foods like bloodworms.
Peacock Eel At a Glance
Peacock Eel Tank Requirements
Will Peacock Eel fit in your tank?
Care guides tell you what Peacock Eel needs, the next question is whether your tank can safely provide it. Test Peacock Eel against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Peacock Eel Water Parameters
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Peacock Eel Temperament & Compatibility
Peacock Eel Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Adult (Standard)
The adult size of the Peacock Eel. Requires a spacious footprint for comfortable burrowing and swimming. Despite their length, their bioload is relatively low due to their slender profile.
Same care requirements as the base species
Also known as: Full Grown
Juvenile (Grow-out)
Peacock Eels are typically sold as juveniles around 8-12cm. They can be temporarily housed in smaller aquariums but will require a rapid upgrade as they grow. Monitor closely during feeding, as they are easily outcompeted by faster fish.
Differs in 4 traits from base species
Also known as: Baby Spiny Eel
Peacock Eel Care Guide Summary
The Peacock Eel, scientifically known as Macrognathus siamensis, belongs to the Oddballs family group. Adults reach a maximum size of approximately 30 cm and have a eel body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the bottom zone of the aquarium and produces a medium level of biological waste.
To thrive, the Peacock Eel requires a freshwater only aquarium with a minimum volume of 150 litres and a tank length of at least 90 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 6.5–8 and a general hardness of 5–15 dGH. A low water flow is preferred.
Due to its specialist needs, the Peacock Eel is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Adult (Standard) and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Peacock Eel Habitat Setup
When setting up an aquarium for the Peacock Eel, a low water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, and dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper and expect substrate disturbance, so lightweight décor should be secured.
Peacock Eel Compatibility Notes
Classified as peaceful, the Peacock Eel is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, ornamental shrimp are not safe companions, shy or slow-feeding tankmates may be outcompeted at feeding time, and boisterous or fast-moving tankmates may cause this species undue stress. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Peacock Eel Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Peacock Eel.
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
Show 9 more tank sizes
Peacock Eel Feeding & Diet Considerations
The Peacock Eel will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups, will eat fry, so breeding efforts in the same tank are unlikely to succeed, is an aggressive eater that may prevent timid tankmates from getting enough food, so target feeding or simultaneous feeding at opposite ends of the tank can help, and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition.
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Frequently Asked Questions About Peacock Eel
How big does Peacock Eel get?
Peacock Eel (Macrognathus siamensis) typically reaches a maximum adult size of approximately 30 cm. They have a eel body shape and a moderate growth rate.
What tank size does Peacock Eel need?
A minimum aquarium volume of 150 litres and a tank length of at least 90 cm are recommended for Peacock Eel. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Peacock Eel need?
Peacock Eel thrives in freshwater only conditions with a temperature range of 23–28°C, a pH between 6.5 and 8, and a general hardness of 5–15 dGH. A low water flow is preferred.
Is Peacock Eel peaceful or aggressive?
Peacock Eel is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
Can Peacock Eel live alone?
Yes, Peacock Eel can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Peacock Eel safe with shrimp?
No. Peacock Eel is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Peacock Eel have any special tank requirements?
Yes. Peacock Eel benefits from sand (sifters), smooth gravel (sensitive barbels), and plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Peacock Eel need a lid on the tank?
Yes. Peacock Eel is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Top Tank Mates for Peacock Eel
These fish are strong compatibility matches for Peacock Eel based on water preferences, temperament, adult size, and tank behavior.
Banded Gourami
Trichogaster fasciata
Ideal Tank MatesLima Shovelnose Catfish
Sorubim lima
Ideal Tank MatesApistogramma Marmor (Marbled Apisto)
Apistogramma erythrura
Ideal Tank MatesGolden Bristlenose Pleco
Ancistrus sp. L144
Ideal Tank MatesApistogramma Resticulosa Mamor
Apistogramma cf. resticulosa Mamor
Ideal Tank MatesBolivian Ram
Mikrogeophagus altispinosus
Ideal Tank MatesPlants That Suit Peacock Eel
These plants pair well with Peacock Eel based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Carolina Mosquito Fern
Azolla caroliniana
Common Duckweed
Lemna minor
Crystalwort
Riccia fluitans
Fish Similar to Peacock Eel
Zebra Spiny Eel
Mastacembelus zebrinus
The Zebra Spiny Eel is a fascinating, small eel-like fish native to the Inle Lake region of Myanmar. Known for its striking vertical stripes and elongated snout, it is a peaceful but shy bottom-dweller. It strictly requires a soft sand substrate to burrow into, as gravel can severely damage its skin and lead to fatal bacterial infections. A micropredator by nature, it will hunt small shrimp and fry but remains entirely peaceful toward appropriately sized tank mates. A tight-fitting lid is absolutely mandatory, as they are notorious escape artists.
Lesser Spiny Eel
Macrognathus aculeatus
A fascinating, elongated bottom-dweller known for its pointed snout. It is primarily nocturnal and spends much of its time buried in the substrate. While peaceful with fish too large to eat, it is an opportunistic predator that will consume small fish, shrimp, and fry. A soft sand substrate is absolutely mandatory to prevent severe bacterial skin infections from burrowing.
Fire Eel
Mastacembelus erythrotaenia
The Fire Eel is a stunning, large species of spiny eel native to Southeast Asia, known for its brilliant red lateral stripes and highly interactive, 'dog-like' personality with owners. As a true 'monster fish', it requires massive aquariums. A soft sand substrate is absolutely mandatory, as they will burrow and suffer lethal bacterial infections from scratching themselves on gravel. They are notorious escape artists and will eat any fish small enough to fit in their mouths.
Half Banded Spiny Eel
Macrognathus circumcinctus
A fascinating, peaceful bottom-dweller with a pointed snout and distinct banding. Like all spiny eels, they are notorious escape artists and require a tightly fitting lid. A soft sand substrate is absolutely mandatory to prevent skin abrasions and subsequent bacterial infections when they burrow. They are nocturnal micropredators that will hunt small shrimp and fry, but remain peaceful toward larger tank mates.
Peacock Gudgeon
Tateurndina ocellicauda
A stunning, peaceful freshwater sleeper goby from Papua New Guinea. Known for their vibrant blue, red, and yellow colors, they are excellent nano-tank inhabitants. They are not true gobies (they lack fused pelvic fins) and are exclusively freshwater. They prefer slow-moving water, dense vegetation, and small caves (like PVC pipes or smooth stones) for spawning.
Peacock Bass Ocellaris
Cichla ocellaris
A massive, incredibly fast-swimming predatory cichlid native to South America. Known for their striking colors and voracious appetite, they are strictly for advanced 'monster fish' keepers. They possess highly expandable mouths and will eat absolutely any fish that fits inside. Despite their predatory nature, they are generally not aggressive towards tank mates they cannot swallow.