Aroa twig catfish

Where they come from

Aroa twig catfish (Farlowella martini) come from slow, warm South American waters where branches, roots, and leaf litter are basically the whole landscape. They are built for that life: skinny, stick-like, and happiest when they can vanish against wood and plants.

If you have ever kept other Farlowella, the vibe is familiar: calm fish, very specialized mouth, and not much tolerance for sloppy water or being outcompeted at dinner.

Setting up their tank

Think of their tank like a quiet river edge full of sticks. They want lots of surfaces to perch on and graze, with gentle flow and stable, clean water. They are not a fish I toss into a new setup.

• Tank size: 20 gallons is workable for one or a pair, but 30+ makes life easier (more grazing room, more stable water).
• Hardscape: real driftwood is your best friend. Add multiple branches angled up and down so they can choose their favorite perch.
• Plants: not required, but helpful. Broad-leaf plants and stem plants give them extra resting spots and make them feel less exposed.
• Filtration: strong biological filtration, but aim the output so the tank has mild, steady circulation instead of blasting them.
• Substrate: anything is fine. I like sand or fine gravel because it is easy to keep clean around all that wood.

Water-wise, they respond best to warm, soft-to-medium water and consistency. Pick a temp in the mid-70s to low-80s F and keep it steady. Big swings, especially after water changes, are where people lose them.

What to feed them

This is the part that makes them "advanced." They graze all day, but they are not lawnmowers that can live off whatever algae shows up. In a clean tank, you have to provide real food, and you have to make sure they actually get it.

• Staples: quality algae wafers and sinking herbivore pellets (I rotate brands so they do not get stuck on one thing).
• Veggies: blanched zucchini, cucumber, green bean, spinach, or romaine. Zucchini is usually the first "yes" food.
• Protein boost: occasional Repashy-style gel foods, or a small amount of meaty sinking food once or twice a week. Not a daily thing.
• Natural grazing: seasoned driftwood and rocks with biofilm are a huge help, especially for newly imported fish.

Watch their body shape. A healthy Farlowella looks slim, but not pinched. If the belly looks hollow or the fish seems to "sharpen" behind the head, it is getting outcompeted or not accepting your foods yet.

How they behave and who they get along with

They are peaceful to a fault. Most of the day they just park on wood, shuffle along slowly, and graze. They are also jumpy in a different way: sudden movement in the room can make them bolt, so a lid is a good idea.

• Good tankmates: small tetras, pencilfish, hatchetfish, rasboras, peaceful dwarf cichlids, Corydoras, Otocinclus (if the tank can support everyone), and other calm bottom fish.
• Tankmates to avoid: big or pushy cichlids, fin-nippers, boisterous barbs, and anything that rushes food.
• Also avoid: plecos that are aggressive eaters or that like to "claim" wood. Twig cats lose that fight.

Breeding tips

Breeding Farlowella is doable, but it is one of those projects where stability matters more than tricks. If you have a well-fed group in a mature tank, they sometimes decide to do the work for you.

• Sexing: males usually develop noticeable odontodes (bristly texture) on the snout and broader head shape. Females tend to look smoother.
• Spawning: eggs are often laid on a flat surface (glass, broad leaf, smooth wood). The male typically guards and fans them.
• Trigger ideas: slightly cooler water changes and heavier feeding for a week or two can help, but do not chase numbers. Keep the tank calm and clean.

Fry are the usual bottleneck: they need constant access to soft foods and grazing surfaces. In practice that means established biofilm, small algae wafers, and powdered or gel foods they can rasp. A bare, sparkling-clean rearing tank sounds safe, but it can starve them.

Common problems to watch for

• Starvation while "there is food in the tank": fast fish ate it first, or the food offered is not something they recognize. Watch belly shape and feed at night.
• New-import decline: they arrive thin and stressed and may not accept wafers right away. Mature tanks with real biofilm and gentle conditions help a lot.
• Poor reaction to big water changes: sudden temp/pH swings can knock them over. Do smaller changes more often.
• Injuries and infections on the snout or body: they scrape themselves on rough decor or during frantic darting. Keep hardscape smooth and avoid sharp rocks.
• Wasting with white stringy poop: can be internal parasites, especially on wild fish. Quarantine is worth your time with this species.
• Getting outcompeted by plecos or "greedy" community fish: they do not fight back, they just slowly lose weight.

The biggest success pattern I have seen is simple: mature tank, lots of wood, calm tankmates, and a feeding routine that assumes they are slow and polite. Do that, and Farlowella martini stop being fragile mystery sticks and start acting like the relaxed little grazers they are.