Should I buy it?
Twig / whiptail catfish
Farlowella acus
Typical trade / ID note: Farlowella species group
Also known as: whiptail catfish, twig catfish, Twig catfish, Whiptail (many Farlowella spp. in trade; verify with supplier)
Fishori provides conservative planning guidance, not guarantees.
Based on typical aquarium care sources; trade names can be ambiguous, so details may vary between setups. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.
A remarkable stick-like algae grazer that needs a consistent algae supply and is sensitive to water quality. Often miscategorised as easy.
Best for
Mature planted tanks 150L or more with consistent algae supply, daily vegetable supplementation, and peaceful companions.
Avoid if
Your tank is under six months old, lacks adequate algae for continuous grazing, or has aggressive fish.
Top things that go wrong
- Shrimp & snails. Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Common mistakeNo vegetable supplementation. Twig catfish cannot survive on algae alone in most home aquariums and need daily blanched cucumber or zucchini.
Common trade-name warning
This fish is often sold under different names or species variants. Care guidance is based on typical aquarium examples rather than a single exact species. Whiptails in shops may be several Farlowella or Sturisoma species; long-snout care is similar, but not every "twig" is F. acus without a positive ID.
What most shops don't tell you
- 1.Sold as a fast-growing algae cleaner for a new tank. The fish starves before the algae arrives.
- 2.Kept in small tanks with fast midwater fish. The twig loses every meal at the glass and slowly thins.
- 3.Long snout/whiptail: watch for nipped tips and damaged barbels. Feed fibre-rich, slow-sinking, and periphyton-appropriate diet once settled (not 'just algae').
About this species
Twig catfish are 20 cm Farlowella that look exactly like a stick of waterlogged wood. Needs fine sand, mature wood biofilm, and a quiet low-competition community. Starves in a bare bright tank with sharp gravel and fast midwater fish.
- Emerald catfish (Brochis)120L min · same group, comparable tank size
- Bronze corydoras100L min · same fish family
- Cuckoo / petricola catfish200L min · same fish family
- Sterba's Corydoras100L min · same fish family
- Upside-down Catfish100L min · same fish family
- Adolfoi cory80L min · same fish family
- Glass Catfish80L min · same fish family
- Peppered Corydoras80L min · same fish family
- Adolfoi coryalso intermediate peaceful, similar tank size
- African freshwater butterflyfishalso intermediate peaceful, similar tank size
- Bamboo Shrimpalso intermediate peaceful, similar tank size
- Black ruby barbalso intermediate peaceful, similar tank size
- Boesemani Rainbowfishalso intermediate peaceful, similar tank size
- Bolivian Ramalso intermediate peaceful, similar tank size
No reverse lookups on file yet.
Plan grid
Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.
Swim zones
Planning trait chart
Six indices for comparing species on paper before you spend.
- Beginner ease32
- Peacefulness82
- Community fit70
- Small-tank fit97
- Hardiness54
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Common setup sketches
Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.
Rough 150L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safe directions on file include: Corydoras Catfish, Ember Tetra, Boesemani Rainbowfish.
Avoid “one of everything” baskets — Twig / whiptail catfish belongs in a plan built around territory, line-of-sight breaks, and matched water chemistry.
Tank mate intelligence
Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Twig / whiptail catfish against your own reading before you buy.
Pair-level compatibility with this fish as anchor.
Read the blocking rule on each pair page before experimenting.
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Twig / whiptail catfish + Corydoras Catfish
Behaviour, temperament, and what to watch
Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.
Twig / whiptail catfish is peaceful in mixed company. Holds territory on substrate, in caves, or at the surface film. Break the sight lines with hardscape to keep the resident off the visitor.
Stress / aggression triggers on file
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper, but individuals can still test fins under stress or in a crowded tank.
Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.
Territory: Holds territory on substrate, in caves, or at the surface film. Break the line of sight with hardscape, and avoid placing the tank where the fish can see its own reflection.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Often calm on the glass — bursts of movement around food or tank disturbance.
- Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
- Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
- Corner guarding, flaring, or body-blocking — territory is normal until it becomes relentless.
- Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
- If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Care parameters: water, food, inverts, grouping
Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.
Hardness
soft
Diet
omnivore
Mixed diet: a quality flake or pellet as the staple, with frozen or live foods two or three times a week.
Shrimp & snails
Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Kept singly or as a paired setup. Check the species profile before doubling up in one tank.
Breeding behaviour depends on the species. Research before you buy a mixed-sex group of this fish.
- Hold 24 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 7.2 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 150L published minimum for adults.
- Heater can hold 24–28°C without cooking cooler-water tank mates.
- No known fin-nippers paired with long-finned fish unless you accept documented risk.
Explore and stocking hubs
Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.
Plan with tools
Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.
Filtration & heating
A 150L minimum tank needs a filter rated for at least 600L/hr turnover and a heater to hold 24–28°C reliably.
Plant suggestions
Twig / whiptail catfish does well in planted tanks. Plants compatible with 24–28°C and pH 6–7.2:
Profile status: partially verified · Evidence tier: medium · 3 linked source(s). Fishori does not fabricate citations.
Fishori uses conservative planning rules based on these sources.
Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- LiveAquaria. Farlowella (twig / whiptail) catfish
Primary: retailer care page specifically titled Farlowella acus: tank size, planted tank use, and feeding when algae is scarce. Trade whiptails are often mixed Farlowella/Sturisoma; confirm snout/head profile from photos, not a single common name.
- Planet Catfish. Farlowella acus (Cat-eLog species sheet)
Primary: hobby data sheet: identification, long-snout care, and typical failure modes (outcompeted, wrong substrate) for this loricariid type.
- FishBase. Farlowella acus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
Evidence notes
- Seriously Fish did not serve a retrievable F. acus profile URL. Retail pages + Planet Catfish are used instead, but the trade label 'whiptail / farlowella' is shared across similar species, so a perfect one-species public page is still rare; identify the import before mirroring pH/length to the letter.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
- Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.