Darwin Feshwater Sole (8cm)

Description

Darwin Freshwater Sole (Brachirus selheimi)

One of Australia's most unusual native freshwater fish, the Darwin Freshwater Sole is a genuine freshwater-to-estuarine flatfish from northern Australia. Perfectly adapted to life on the bottom, Brachirus selheimi spends much of its time camouflaged against sand and substrate, waiting for small crustaceans, insects and fish to come within striking distance. If you want an Australian native that looks and behaves unlike almost anything else in the aquarium, this is it.

Quick Facts

  • Scientific name: Brachirus selheimi
  • Common names: Darwin Freshwater Sole, Freshwater Sole, Selheim's Sole
  • Origin: Northern Australia
  • Habitat: Freshwater rivers and brackish estuaries
  • Current size: Varies between individuals
  • Adult size: Up to approximately 15 cm
  • Tank size: 100L+ recommended
  • Difficulty: 🔴 Moderate to Advanced
  • Temperament: Generally peaceful but predatory
  • Best kept: In a specialised aquarium with a large area of fine substrate and carefully selected tank mates

Is this for you?

✔️ Perfect if:

  • You love unusual Australian native fish.
  • You want something genuinely different from conventional aquarium species.
  • You enjoy observing natural predatory and camouflage behaviour.
  • You can provide a large area of fine sand and excellent water quality.
  • You are comfortable feeding carnivorous fish appropriately.

❌ Avoid if:

  • You want a conventional active community fish.
  • You keep tiny fish or shrimp that could become prey.
  • You expect the fish to eat flakes immediately after arrival.
  • Your aquarium has coarse or sharp substrate.
  • You want a fish that spends most of its time swimming visibly through open water.

Why choose the Darwin Freshwater Sole?

The Darwin Freshwater Sole is one of those fish that makes people stop and ask, "What is that?"

Like other flatfish, juvenile soles begin life with an eye on each side of the head. During development, one eye migrates to the other side and the fish transitions to a bottom-dwelling lifestyle.

The result is an extraordinary fish designed to lie almost completely flat against the substrate. Its mottled brown colouration provides excellent camouflage against sand, mud and natural debris, allowing it to virtually disappear while waiting for food.

This isn't a fish selected by breeders for an unusual body shape. This is how the species naturally evolved to survive in Australian waterways.

Benefits

  • Australian native species
  • One of the most unusual freshwater fish available
  • Natural flatfish body shape
  • Exceptional camouflage behaviour
  • Fascinating ambush-predator feeding behaviour
  • Manageable adult size compared with many flatfish
  • Outstanding feature species for Australian native aquariums

Care made simple

  • Temperature: Tropical to warm-temperate conditions appropriate to northern Australian freshwater fish
  • Water: Clean, stable and well oxygenated
  • Salinity: Naturally occurs in both freshwater and brackish environments
  • Substrate: Fine sand is strongly recommended
  • Setup: Provide extensive open sandy areas combined with sheltered structure around the edges of the aquarium
  • Diet: Carnivorous – small crustaceans, aquatic insects, worms and appropriately sized meaty foods
  • New arrivals may require live or highly attractive frozen foods before accepting prepared foods.
  • Avoid housing with tiny fish or shrimp that could be swallowed.
  • Ensure food actually reaches the sole rather than being consumed by faster tank mates.

Pairs perfectly with

  • Appropriately sized Australian Rainbowfish
  • Larger Australian native gudgeons
  • Other peaceful native fish too large to be swallowed
  • Australian biotope-style aquariums
  • Fine sand, driftwood, rocks and natural leaf litter
NTA Insight:
This isn't a fish we recommend buying and simply dropping into a normal community aquarium. The Darwin Freshwater Sole is a specialised bottom-dwelling predator. Fine sand, appropriate meaty foods and making sure it actually gets fed are far more important than trying to keep it as a conventional ornamental fish. Don't be surprised if it disappears against the substrate—that camouflage is exactly what makes this species so fascinating.

FAQ

Is the Darwin Freshwater Sole really a freshwater fish?

Yes. Brachirus selheimi naturally occurs in freshwater rivers as well as brackish estuarine environments in northern Australia. It is therefore unusual amongst flatfish, most of which are primarily marine.

Is it an Australian native?

Yes. Brachirus selheimi is an Australian native freshwater and estuarine species found across parts of northern Australia.

How large does the Darwin Freshwater Sole grow?

Adults can reach approximately 15 cm total length, making this a relatively compact flatfish but still requiring substantially more bottom area than its length alone might suggest.

Why are both eyes on the same side?

Young flatfish begin development with eyes on opposite sides of the head. As the fish develops, one eye migrates across the head and the body becomes adapted to lying flat against the substrate.

What does a Darwin Freshwater Sole eat?

It is carnivorous. In nature, Brachirus selheimi feeds on small fishes, crustaceans and aquatic insects. Aquarium specimens should therefore receive an appropriate variety of meaty foods.

Will it eat pellets and flakes?

Do not assume that it will, particularly when newly introduced. Some individuals may need to be conditioned onto non-living foods gradually. Live and frozen foods that trigger a natural feeding response may initially be required.

Can Darwin Freshwater Sole live with shrimp?

We would not recommend valuable shrimp as tank mates. Crustaceans form part of the species' natural diet, so appropriately sized shrimp should be considered potential prey.

Can it live with small fish?

Use caution. Small fish form part of the natural diet of Brachirus selheimi. Tank mates should therefore be peaceful but sufficiently large that they cannot reasonably be swallowed.

Does it need sand?

Fine sand is strongly recommended. Freshwater Soles are specialised bottom dwellers and naturally occur over sandy and other soft substrates. A broad area of fine substrate allows them to rest and camouflage naturally.

Does it need brackish water?

The species occurs naturally in both freshwater rivers and brackish estuarine habitats. It should not be confused with flatfish species that are routinely sold as "freshwater" despite requiring brackish conditions long-term. Stability and knowing the conditions in which your particular fish has been maintained remain important.

Why can't I find my Freshwater Sole?

Look carefully at the substrate. Their mottled upper surface provides excellent camouflage, and a settled fish lying motionless against sand can be surprisingly difficult to see.

Is the Darwin Freshwater Sole suitable for beginners?

We would not classify it as a beginner fish. The challenge is not necessarily aggression or extreme water chemistry, but providing appropriate substrate, selecting safe tank mates and ensuring a specialised bottom-dwelling predator receives enough suitable food.

Darwin Feshwater Sole (8cm)

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Out of stock,  

$100.00  $80.00


All prices include GST
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    Description

    Darwin Freshwater Sole (Brachirus selheimi)

    One of Australia's most unusual native freshwater fish, the Darwin Freshwater Sole is a genuine freshwater-to-estuarine flatfish from northern Australia. Perfectly adapted to life on the bottom, Brachirus selheimi spends much of its time camouflaged against sand and substrate, waiting for small crustaceans, insects and fish to come within striking distance. If you want an Australian native that looks and behaves unlike almost anything else in the aquarium, this is it.

    Quick Facts

    • Scientific name: Brachirus selheimi
    • Common names: Darwin Freshwater Sole, Freshwater Sole, Selheim's Sole
    • Origin: Northern Australia
    • Habitat: Freshwater rivers and brackish estuaries
    • Current size: Varies between individuals
    • Adult size: Up to approximately 15 cm
    • Tank size: 100L+ recommended
    • Difficulty: 🔴 Moderate to Advanced
    • Temperament: Generally peaceful but predatory
    • Best kept: In a specialised aquarium with a large area of fine substrate and carefully selected tank mates

    Is this for you?

    ✔️ Perfect if:

    • You love unusual Australian native fish.
    • You want something genuinely different from conventional aquarium species.
    • You enjoy observing natural predatory and camouflage behaviour.
    • You can provide a large area of fine sand and excellent water quality.
    • You are comfortable feeding carnivorous fish appropriately.

    ❌ Avoid if:

    • You want a conventional active community fish.
    • You keep tiny fish or shrimp that could become prey.
    • You expect the fish to eat flakes immediately after arrival.
    • Your aquarium has coarse or sharp substrate.
    • You want a fish that spends most of its time swimming visibly through open water.

    Why choose the Darwin Freshwater Sole?

    The Darwin Freshwater Sole is one of those fish that makes people stop and ask, "What is that?"

    Like other flatfish, juvenile soles begin life with an eye on each side of the head. During development, one eye migrates to the other side and the fish transitions to a bottom-dwelling lifestyle.

    The result is an extraordinary fish designed to lie almost completely flat against the substrate. Its mottled brown colouration provides excellent camouflage against sand, mud and natural debris, allowing it to virtually disappear while waiting for food.

    This isn't a fish selected by breeders for an unusual body shape. This is how the species naturally evolved to survive in Australian waterways.

    Benefits

    • Australian native species
    • One of the most unusual freshwater fish available
    • Natural flatfish body shape
    • Exceptional camouflage behaviour
    • Fascinating ambush-predator feeding behaviour
    • Manageable adult size compared with many flatfish
    • Outstanding feature species for Australian native aquariums

    Care made simple

    • Temperature: Tropical to warm-temperate conditions appropriate to northern Australian freshwater fish
    • Water: Clean, stable and well oxygenated
    • Salinity: Naturally occurs in both freshwater and brackish environments
    • Substrate: Fine sand is strongly recommended
    • Setup: Provide extensive open sandy areas combined with sheltered structure around the edges of the aquarium
    • Diet: Carnivorous – small crustaceans, aquatic insects, worms and appropriately sized meaty foods
    • New arrivals may require live or highly attractive frozen foods before accepting prepared foods.
    • Avoid housing with tiny fish or shrimp that could be swallowed.
    • Ensure food actually reaches the sole rather than being consumed by faster tank mates.

    Pairs perfectly with

    • Appropriately sized Australian Rainbowfish
    • Larger Australian native gudgeons
    • Other peaceful native fish too large to be swallowed
    • Australian biotope-style aquariums
    • Fine sand, driftwood, rocks and natural leaf litter
    NTA Insight:
    This isn't a fish we recommend buying and simply dropping into a normal community aquarium. The Darwin Freshwater Sole is a specialised bottom-dwelling predator. Fine sand, appropriate meaty foods and making sure it actually gets fed are far more important than trying to keep it as a conventional ornamental fish. Don't be surprised if it disappears against the substrate—that camouflage is exactly what makes this species so fascinating.

    FAQ

    Is the Darwin Freshwater Sole really a freshwater fish?

    Yes. Brachirus selheimi naturally occurs in freshwater rivers as well as brackish estuarine environments in northern Australia. It is therefore unusual amongst flatfish, most of which are primarily marine.

    Is it an Australian native?

    Yes. Brachirus selheimi is an Australian native freshwater and estuarine species found across parts of northern Australia.

    How large does the Darwin Freshwater Sole grow?

    Adults can reach approximately 15 cm total length, making this a relatively compact flatfish but still requiring substantially more bottom area than its length alone might suggest.

    Why are both eyes on the same side?

    Young flatfish begin development with eyes on opposite sides of the head. As the fish develops, one eye migrates across the head and the body becomes adapted to lying flat against the substrate.

    What does a Darwin Freshwater Sole eat?

    It is carnivorous. In nature, Brachirus selheimi feeds on small fishes, crustaceans and aquatic insects. Aquarium specimens should therefore receive an appropriate variety of meaty foods.

    Will it eat pellets and flakes?

    Do not assume that it will, particularly when newly introduced. Some individuals may need to be conditioned onto non-living foods gradually. Live and frozen foods that trigger a natural feeding response may initially be required.

    Can Darwin Freshwater Sole live with shrimp?

    We would not recommend valuable shrimp as tank mates. Crustaceans form part of the species' natural diet, so appropriately sized shrimp should be considered potential prey.

    Can it live with small fish?

    Use caution. Small fish form part of the natural diet of Brachirus selheimi. Tank mates should therefore be peaceful but sufficiently large that they cannot reasonably be swallowed.

    Does it need sand?

    Fine sand is strongly recommended. Freshwater Soles are specialised bottom dwellers and naturally occur over sandy and other soft substrates. A broad area of fine substrate allows them to rest and camouflage naturally.

    Does it need brackish water?

    The species occurs naturally in both freshwater rivers and brackish estuarine habitats. It should not be confused with flatfish species that are routinely sold as "freshwater" despite requiring brackish conditions long-term. Stability and knowing the conditions in which your particular fish has been maintained remain important.

    Why can't I find my Freshwater Sole?

    Look carefully at the substrate. Their mottled upper surface provides excellent camouflage, and a settled fish lying motionless against sand can be surprisingly difficult to see.

    Is the Darwin Freshwater Sole suitable for beginners?

    We would not classify it as a beginner fish. The challenge is not necessarily aggression or extreme water chemistry, but providing appropriate substrate, selecting safe tank mates and ensuring a specialised bottom-dwelling predator receives enough suitable food.

    Live Arrival & Ordering FAQ

    Why do livestock prices sometimes change?

    Unlike manufactured products, fish and shrimp continue to grow and develop over time. Their value changes as they increase in size, develop colour, or become breeding pairs.

    Our prices are based on the current size, quality and availability of each specimen. While pricing often remains stable for around 3–4 months, it may be updated at any time to reflect these changes.

    We always aim to offer healthy, high-quality livestock at fair and competitive prices.

    Do you offer a live arrival guarantee?

    Yes. All livestock is covered by our Live Arrival Guarantee.

    In the rare event of DOA, please contact us promptly with clear photos of the livestock in the original unopened bag.

    Please review our full DOA and store policies before purchase.

    Can you ship to all states in Australia?

    No. Due to state restrictions, we cannot ship livestock or live plants to WA and TAS.

    What should I check before ordering?

    Before placing an order, make sure:

    • Your tank is fully cycled and stable
    • Your aquarium has enough space for the species
    • Your current livestock are compatible in temperament, size, and requirements
    • Your water parameters, habitat, and temperature suit the species
    • You are not adding too many fish at once
    What should I expect when my fish arrives?

    It is normal for fish, shrimp, or snails to look pale, stressed, or less active after shipping.

    This is temporary. Most livestock will settle and regain colour within a few days.

    How long does it take for fish to settle in?

    Most livestock will take 3–7 days to fully adjust to their new environment.

    Should I feed my fish immediately after arrival?

    No. We recommend waiting 24 hours before feeding to allow them to settle.

    If you already have fish in your tank, feeding them before introducing new arrivals can help reduce stress.

    Why do fish sometimes struggle after being added to a tank?

    In most cases, issues are caused by tank conditions, not shipping.

    • Uncycled or unstable tanks
    • Poor water parameters
    • Overstocking
    • Unsuitable tank mates
    What is Nano Tanks Australia’s main tip for new livestock?

    Most livestock losses happen in immature or unstable tanks, not during shipping.

    If your setup is not fully established, the risk to new arrivals is significantly higher.

    Not sure if this fish is right for your setup?

    If you are unsure whether this species suits your setup, contact us before ordering and we’ll help point you in the right direction.

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