
Chocolate-colored catfish
Rineloricaria lanceolata
Also known as: Chocolate whiptail catfish
This is a slim little whiptail (a Loricariid) that spends most of its time gliding over sand and leaves, picking at biofilm like a tiny vacuum cleaner. Give it driftwood, caves, and calm tankmates and it turns into a super chill, sneaky-bottom-dweller with that awesome long whip tail and high dorsal fin.

The Chocolate-colored catfish features a slender, elongated body with dark brown to chocolate hues, complemented by fine, bristle-like barbels.
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Quick Facts
Size
12.3 cm
Temperament
Peaceful
Difficulty
Intermediate
Min Tank Size
20 gallons
Lifespan
8-12 years
Origin
South America
Diet
Omnivore - biofilm/algae wafers, sinking pellets, blanched veggies, plus occasional frozen/live small inverts
Care Notes
- Give them real floor space and flow - a 20 long is a better starter than a tall tank, with sand or smooth fine gravel so they do not grind up their belly and fins.
- They chill under wood and rocks all day, so pack in driftwood, caves, and leaf litter; they get way bolder once they have multiple hideouts.
- Keep the water in the middle range: about 74-80F, pH 6.5-7.6, and low-ish nitrates (try to stay under ~20 ppm) or you will see them get skinny and lethargic.
- Feed after lights out - sinking wafers, Repashy-style gel foods, and frozen bloodworms or brine; they are not a pure algae crew and will starve if you just hope they graze.
- Tankmates: peaceful community fish are fine (tetras, rasboras, corys), but skip fin-nippers and big pushy cichlids that will harass them and steal all the food.
- Watch for bloat and pinched bellies from underfeeding or too much dry food - mix in frozen foods and do smaller portions more often.
- Breeding is fun if you add a few tight caves or short lengths of PVC - the male guards the eggs, so do not keep rearranging the tank once a pair picks a spot.
Compatibility
Good Tankmates
- Small, chill tetras (neons, rummynose, lemons) - they stay midwater and ignore the catfish, and the Rineloricaria just cruises the bottom doing its own thing
- Corydoras groups - peaceful bottom buddies that usually share space fine as long as the tank footprint is decent and you have more than one hiding spot
- Small rasboras and danios (harlequins, lambchops, celestial pearls, zebra danios) - active but not mean, and they do not compete much for the same food if you drop in sinking stuff after lights out
- Dwarf cichlids that are on the calm side (Apistogramma, Bolivian ram) - works when you give caves and keep breeding drama in check, because the catfish is not looking for trouble
- Other gentle bottom fish like Otocinclus - similar vibe, just make sure there is enough biofilm/veg and you supplement with wafers or blanched veg
- Peaceful livebearers (platies, mollies, guppies) - generally fine, just keep up with feeding so the catfish actually gets its share and does not get outcompeted
Avoid
- Big aggressive cichlids (oscars, convicts, green terrors) - they will hassle it and can chew on the long tail and fins, especially at night when the catfish is out
- Nippy fin-biters (tiger barbs, serpae tetras) - that long whippy tail is basically a snack to them, and the catfish will not really fight back
- Territorial bottom bruisers (most big plecos, some larger Synodontis) - too much competition for caves and food, and you can get constant shoving matches
Where they come from
Rineloricaria lanceolata is one of those South American "stick" or whiptail-type catfish that shows up from flowing river systems with lots of sand, leaf litter, and sunken wood. Mine always acted like a fish that expects current and clean water, not a stagnant puddle. The chocolate-brown look is a great camouflage for that whole driftwood-and-leaves vibe.
If you are used to chunky plecos, this one is different. Think slim, skittish, and more into browsing and perching than bulldozing decor.
Setting up their tank
Give them floor space and a layout they can "lean" on. They spend a lot of time on the substrate, on wood, or wedged under something with just the snout sticking out.
- Tank size: a 20 long works for one, but 30-40 gallons is a lot nicer if you want a small group
- Substrate: sand or very smooth fine gravel (sharp gravel can scrape them up)
- Hardscape: real driftwood and a couple of caves or tight hides (ceramic tubes, half coconut, rock overhangs)
- Flow and filtration: moderate flow and good biofiltration; they appreciate oxygenated water
- Plants: tough plants or plants tied to wood/rock (anubias, java fern); they will not usually uproot, but they do scoot around
I like adding at least one narrow cave or tube where only the whiptail fits. It cuts down on stress, and if you ever try breeding, the male will claim it.
Water numbers do not need to be extreme. Slightly acidic to neutral is fine, and mid-range tropical temps work well. What they react to more than a specific pH is dirty water and low oxygen. If your glass gets a dusty biofilm and your tank has a gentle current, they will be out more and look better.
What to feed them
They are not strict algae eaters. They will graze, but if you only count on algae, they slowly get skinny and you end up wondering why. Mine did best on a mix of sinking foods and fresh stuff.
- Staples: sinking wafers/pellets meant for catfish or bottom feeders
- Veggies: zucchini, cucumber, blanched spinach, green beans (remove leftovers the next day)
- Protein a couple times a week: frozen bloodworms, brine shrimp, daphnia, or a small pinch of quality frozen mix
- Natural grazing: driftwood and biofilm (still feed them, but this helps)
Watch their bellies. A healthy fish has a gently rounded belly, not a pinched-in look behind the head. In community tanks they can get outcompeted at feeding time, especially with fast tetras and greedy cories.
I usually feed after lights-out or right at dusk. They are bolder then, and you will actually see them come out and pick at food instead of waiting until everything is gone.
How they behave and who they get along with
Chocolate-colored catfish are pretty chill. They perch, scoot, and do little bursts of speed from hide to hide. The only real drama I have seen is mild shoving between males over a favorite cave.
- Good tankmates: small to medium peaceful fish like tetras, rasboras, hatchetfish, apistos (watch caves), peaceful barbs, and most dwarf cichlids if there are enough hides
- Also fine: corydoras (they share space well if the tank is not cramped)
- Avoid: fin-nippers, very boisterous cichlids, and big predatory fish that see slim catfish as snacks
- Shrimp: adults are usually left alone, but tiny shrimp can disappear in any community setup
If you keep more than one, give more hides than fish. That one change fixes 90% of the "why are they always stressed" problems.
Breeding tips
They can breed in aquariums, and the pattern is pretty classic whiptail: eggs laid in a cave or tight spot, then the male guards and fans them. You will get the best odds if the fish already feel settled and you have the right kind of caves.
- Use caves/tubes with one entrance and a snug fit (PVC sections work if you do not mind the look)
- Keep water clean and well-oxygenated; a little extra flow past the cave seems to help
- Condition with good food for a few weeks (wafers plus frozen foods and veggies)
- A cooler water change can act like a "rainy season" hint if they are already mature
If you spot a male parked in a cave for days and chasing others away, do not keep peeking and moving the cave. Let him do his job. Spooked males will abandon eggs.
Fry are small and need frequent tiny foods. If you get a hatch, think along the lines of powdered fry food, crushed flakes, baby brine shrimp, and plenty of biofilm on wood. A sponge filter is your friend here.
Common problems to watch for
- Starvation in busy community tanks: they look "fine" until they suddenly do not; target-feed after dark
- Scrapes and mouth damage: usually from sharp gravel, rough rocks, or getting pinned in a tight decor gap
- Low oxygen stress: hanging near the surface or acting extra skittish can mean you need more surface agitation
- Skinny disease from internal parasites: new imports can come in thin; quarantine and treat if they do not gain weight with good feeding
- Sensitivity to meds: like many catfish, they can react poorly to strong doses; go slow and research before dumping in treatments
The biggest mistake I see is treating them like "maintenance crew" instead of a real fish that needs dinner. Feed them intentionally and you will have a much tougher, more visible whiptail.
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