A rare and captivating bottom-dwelling flatfish native to Australia and New Guinea. As an ambush predator, it spends most of its time completely buried in fine sand, waiting to strike at small fish or crustaceans. It absolutely requires a soft sand substrate to thrive and prevent severe abrasions to its delicate underside.
Freshwater Sole At a Glance
Freshwater Sole Tank Requirements
Will Freshwater Sole fit in your tank?
Care guides tell you what Freshwater Sole needs, the next question is whether your tank can safely provide it. Test Freshwater Sole against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Freshwater Sole Water Parameters
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Freshwater Sole Temperament & Compatibility
Freshwater Sole Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard representation of the Freshwater Sole in the aquarium hobby. They are nearly impossible to visually sex. They are peaceful towards large tank mates but will actively eat any fish or invertebrate that can fit in their unexpectedly large mouths.
Same care requirements as the base species
Also known as: Wild Type
Freshwater Sole Care Guide Summary
The Freshwater Sole, scientifically known as Brachirus selheimi, belongs to the Oddballs family group. Adults reach a maximum size of approximately 15 cm and have a depressed body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the bottom zone of the aquarium and produces a medium level of biological waste.
To thrive, the Freshwater Sole requires a brackish tolerant aquarium with a minimum volume of 110 litres and a tank length of at least 90 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 6.5–7.8 and a general hardness of 5–15 dGH. A low water flow is preferred.
Due to its specialist needs, the Freshwater Sole is best suited for fishkeepers who can provide a carefully planned setup. The Freshwater Sole is typically available in one standard form.
Freshwater Sole Habitat Setup
When setting up an aquarium for the Freshwater Sole, 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. Keepers should note that expect substrate disturbance, so lightweight décor should be secured.
Freshwater Sole Compatibility Notes
Classified as mostly peaceful, the Freshwater Sole is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten, ornamental shrimp are not safe companions, 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.
Freshwater Sole Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Freshwater Sole.
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 10 more tank sizes
Freshwater Sole Feeding & Diet Considerations
The Freshwater Sole is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided, 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, 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 Freshwater Sole
How big does Freshwater Sole get?
Freshwater Sole (Brachirus selheimi) typically reaches a maximum adult size of approximately 15 cm. They have a depressed body shape and a moderate growth rate.
What tank size does Freshwater Sole need?
A minimum aquarium volume of 110 litres and a tank length of at least 90 cm are recommended for Freshwater Sole. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Freshwater Sole need?
Freshwater Sole thrives in brackish tolerant conditions with a temperature range of 22–28°C, a pH between 6.5 and 7.8, and a general hardness of 5–15 dGH. A low water flow is preferred.
Is Freshwater Sole peaceful or aggressive?
Freshwater Sole is classified as mostly peaceful with an aggression score of 4 out of 10. They are generally well-suited to peaceful community tanks.
Can Freshwater Sole live alone?
Yes, Freshwater Sole can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Freshwater Sole safe with shrimp?
No. Freshwater Sole 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 Freshwater Sole have any special tank requirements?
Yes. Freshwater Sole benefits from sand (sifters) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Top Tank Mates for Freshwater Sole
These fish are strong compatibility matches for Freshwater Sole based on water preferences, temperament, adult size, and tank behavior.
Moonlight Gourami
Trichogaster microlepis
Ideal Tank MatesFestivum
Mesonauta festivus
Ideal Tank MatesFalse Glass Catfish
Kryptopterus macrocephalus
Ideal Tank MatesBetta Imbellis
Betta imbellis
Ideal Tank MatesBanded Gourami
Trichogaster fasciata
Ideal Tank MatesGold Spot Pleco (L001 / L022)
Pterygoplichthys joselimaianus
Ideal Tank MatesPlants That Suit Freshwater Sole
These plants pair well with Freshwater Sole 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 Freshwater Sole
Freshwater Flounder
Trinectes maculatus
Despite the trade name 'Freshwater Flounder', Trinectes maculatus is actually a euryhaline flatfish native to coastal estuaries in North America. While juveniles migrate into fresh water, adults require at least low-end brackish water (SG 1.005+) for long-term health and a normal lifespan. They are highly specialized, nocturnal ambush predators that spend most of their time buried in fine sand. Keeping them on sharp gravel will severely damage their undersides and lead to infection.
Arrowhead Puffer
Pao suvattii
A highly predatory freshwater pufferfish native to the Mekong basin. Named for its V-shaped, flattened head, it is a specialized ambush predator that buries itself in sand with only its eyes and upwards-facing mouth exposed. It is notoriously aggressive and will consume or fatally bite any tankmate, regardless of size. Must be kept strictly solitary.
Murray River Rainbowfish
Melanotaenia fluviatilis
A robust and active schooling fish native to the cooler waters of the Murray-Darling basin in Australia. Unlike many tropical rainbowfish, it thrives in subtropical or unheated aquariums at normal room temperatures. They are peaceful but extremely fast swimmers, requiring long tanks with plenty of open swimming space.
Parnahyba Whiptail Catfish
Loricaria parnahybae
A distinctive, slender armored catfish native to the Parnaíba River basin in Brazil. Known for its extremely elongated tail and flattened body, it blends perfectly with sandy substrates. It is a peaceful, fascinating bottom-dweller. Like other members of the genus Loricaria, they are remarkable 'lip brooders', where males carry clusters of eggs attached to their enlarged lower lips until they hatch.
Freshwater Shark (Wallago)
Wallago attu
An apex predator native to South and Southeast Asia, infamous for its immense size, huge mouth, and voracious predatory nature. It will consume any tank mate that fits into its capacious mouth and is known to bite aggressively when handled. This species is utterly unsuitable for standard home aquariums and requires an enormous custom pond or public aquarium setup.
Crimsonspotted Rainbowfish
Melanotaenia duboulayi
A highly active, schooling freshwater fish endemic to eastern Australia, often considered the original 'Australian Rainbowfish' in the aquarium trade. Recognizable by a prominent crimson red spot on the operculum (gill cover) and striking silvery-blue to greenish bodies. They are peaceful but extremely vigorous swimmers, requiring plenty of horizontal swimming space and a tight-fitting lid to prevent jumping.