Hyrtl's catfish
Neosilurus hyrtlii
Hyrtl's catfish features a robust, elongated body with a dark brown to olive-green coloration and distinct, long barbels on the snout.
This page includes AI-generated images. Why am I seeing AI images?
About the Hyrtl's catfish
This is an Aussie eel-tail catfish that looks like a sleek little catfish-meets-eel, especially when it flashes those yellow fins. It spends a lot of time cruising the bottom and hoovering up meaty bits, and it can get way bigger than people expect if you keep it well fed and give it swimming room.
Also known as
Quick Facts
Size
34 cm SL
Temperament
Peaceful
Difficulty
Intermediate
Min Tank Size
75 gallons
Lifespan
8-15 years
Origin
Australia
Diet
Carnivore/invertivore - insects, worms, crustaceans, prawns, mollusks; in tanks use sinking pellets plus frozen/live foods
Water Parameters
22-28°C
6.8-8
0-30 dGH
Need a heater for this species?
This species needs 22-28°C in a 75 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Give them a long tank with open sand and a couple of chunky hiding spots (PVC pipe, driftwood caves) - they cruise the bottom and want somewhere to wedge in during the day.
- They handle a range, but they sulk fast in dirty water: keep ammonia/nitrite at 0, nitrates low, and run decent flow with lots of oxygen (think river fish vibes).
- Aim around 24-28C and neutral-ish pH (about 6.5-7.8); stability beats chasing perfect numbers, especially after water changes.
- Feed after lights-out if you want to actually see them eat - sinking carnivore pellets plus frozen prawns, mussel, bloodworms, and the occasional earthworm works great.
- Skip tiny tankmates and anything that sleeps on the bottom; they are not a piranha, but small fish and shrimp can vanish, and slow bottom fish get bullied or outcompeted.
- Good picks are midwater fish that can handle flow and are too big to be snacks (rainbowfish, larger tetras, sturdy barbs); avoid fin-nippers because this catfish will get stressed and hide.
- Watch the belly and barbels: a pinched belly means its not getting food, and frayed barbels usually means sharp gravel or filthy substrate - sand and regular siphoning fix most of that.
- Breeding in tanks is uncommon; if you ever see a fat female and chasing after big water changes, add more caves and keep the lights dim, but dont count on easy fry without a dedicated setup.
Compatibility
Good Tankmates
- Other laid-back Aussie rainbows (Melanotaenia and Glossolepis) - they stay mid to top, dont hassle the catfish, and handle the same warm, clean water. Just give the catfish caves so it can nap all day and cruise at dusk.
- Peaceful tetras and rasboras (think rummynose, lemons, harlequins) - quick little midwater fish that dont get in its face. The catfish mostly ignores them if its well fed.
- Corydoras and other gentle bottom crews - works fine if the tank has enough floor space and multiple hides. Feed spread out so the Hyrtls catfish doesnt just bulldoze the food pile.
- Bristlenose pleco (Ancistrus) - solid match in my experience. Both are chill, just make sure there are more caves than fish so nobody argues over the same favorite spot.
- Small to medium peaceful gouramis (honeys, pearls) - they hang up top and dont mess with the catfish. Avoid the really pushy types if your tank is tight.
- Peaceful barbs and danios (cherry barbs, zebra danios) - active but usually not mean. They keep the middle busy while the catfish does its evening patrol.
Avoid
- Big aggressive cichlids (oscars, convicts, jaguar types) - they will stress it out, steal its cave, and eventually turn it into a chew toy. Not worth trying.
- Fin nippers and hyper-territorial stuff (tiger barbs in small groups, some serpae tetras) - the catfish is peaceful and slow-ish at rest, so it becomes an easy target when its parked under a log.
- Other large predatory catfish or anything with a huge mouth (redtail cats, large pimelodids) - once they size up your Hyrtls as a snack or a rival, it goes downhill fast.
- Super territorial bottom fish in cramped setups (big mature male plecos, some loaches when packed in) - not always a problem, but cave wars are real. If you cant provide extra hides, skip it.
Where they come from
Hyrtl's catfish (Neosilurus hyrtlii) is an Aussie, coming out of northern Australia and southern New Guinea. Think warm floodplains, slow rivers, and billabong-style backwaters with soft bottoms and lots of leaf litter. That background explains a lot about how they act in our tanks: they like cover, they like food on the bottom, and they do best when the setup feels a bit "messy" in a natural way.
Setting up their tank
These are bottom-oriented catfish with a chunky body and a habit of wedging themselves into spots you swear are too small. Give them floor space more than height. For an adult, I'd treat a 40 breeder (or similar footprint) as a starting point, and bigger is always easier on everyone.
- Tank size: aim for a larger footprint tank; adults appreciate 3-4 feet of length
- Substrate: sand is my first pick; smooth fine gravel can work, but avoid sharp stuff
- Cover: driftwood, rock piles (stable), and a couple of snug caves/tubes
- Plants: hardy plants or plants tied to wood/rock; they can bulldoze delicate stems
- Filtration: solid biofiltration and decent turnover; they like clean water but not a blasting current everywhere
- Lighting: they are more comfortable with dimmer areas and shade
If you add leaf litter (Indian almond, oak, etc.), they use it like a security blanket. It also helps you get that natural, subdued look they seem to settle into.
Water-wise, keep it warm and steady. Mid-70s to low-80s F is a comfortable range for most setups, with neutral-ish pH. They are not super fussy, but they do react to swings. The biggest quality-of-life upgrade you can give them is stable parameters and good oxygenation at night (air stone or surface agitation).
Check every decoration for pinch points. They will cram themselves behind heaters, under filters, and into rock gaps. Secure rocks on the glass (or on egg crate) before adding substrate so nothing shifts and traps them.
What to feed them
They are classic opportunistic catfish. Mine acted like vacuum cleaners, but they still did better when I fed with intent instead of assuming they'd live off leftovers. Aim for a meaty, sinking diet with variety.
- Staples: quality sinking carnivore pellets or catfish wafers
- Frozen: bloodworms, blackworms, brine shrimp, mysis, chopped prawn/shrimp
- Fresh: earthworms (rinsed), small bits of fish or shrimp as an occasional treat
- Optional: live foods if you trust the source (quarantine or culture your own when possible)
Feed after lights out or at least at dusk. If you have fast midwater fish, use feeding tongs or drop food right in front of the cave entrance so the catfish actually gets its share.
Portion control matters. They will keep eating if food keeps appearing, and a chubby catfish plus a dirty substrate is a quick path to algae, cloudy water, and health issues. I prefer smaller feedings 4-6 days a week, then a lighter day or a skip day.
How they behave and who they get along with
Expect a shy fish at first. Once they learn the routine, you'll see them cruise the bottom at feeding time and then disappear back into cover. They are peaceful overall, but they are still a predator with a big mouth - if it fits, it is food.
- Temperament: generally calm, can be territorial about a favorite hide
- Activity: mostly crepuscular/nocturnal, but can become bolder with a predictable routine
- Best tankmates: medium-sized peaceful fish that stay midwater (rainbowfish, larger tetras, peaceful cichlids that are not hyper-aggressive)
- Avoid: tiny fish and shrimplets, fin-nippers, and aggressive bottom fish that will fight for caves
- Bottom companions: choose carefully; if you want other bottom dwellers, provide extra hides and spread them out
They are one of those fish that look "lazy" until you watch at night. A cheap red/blue moonlight or a quick look with a flashlight will show you they actually roam a lot.
Keeping more than one can work, but you need space and multiple hides. In tighter tanks, one will often claim the best cave and the other stays stressed. If you try a group, add them together while young and build a tank with lots of broken sight lines.
Breeding tips
Breeding Neosilurus in home tanks is possible but not something most people stumble into by accident. They are not like bristlenose where you toss in a cave and get babies. If you want to try, think seasonal changes: warmer wet-season cues, heavier feeding, and lots of secure spawning spots.
- Conditioning: feed heavy on meaty frozen/live foods for a few weeks
- Cues: a big water change with slightly cooler water can mimic rain
- Spawning spots: caves/tubes and tight wood crevices; keep them roomy enough that a fish can turn around without scraping
- Egg/fry care: be ready to separate adults if you see eggs or tiny fry - they are not reliable parents in community tanks
If you are serious about breeding, a species tank is the easiest route. In a busy community, you may never even notice eggs, and any fry that hatch usually get picked off fast.
Common problems to watch for
Most issues I have seen with Hyrtl's catfish were setup and feeding related, not mystery diseases. Fix the environment and the fish usually perks up quickly.
- Barbel wear/infection: usually from sharp gravel, dirty substrate, or constant scraping in rough caves
- Getting outcompeted for food: shows up as weight loss even though the tank is "well fed"
- Bloat/constipation: from overfeeding rich foods or too many pellets; vary the diet and cut portions
- Stress from lack of cover: they hide nonstop, breathe fast, or wedge into unsafe spots
- Ammonia/nitrite sensitivity: bottom fish feel it first; watch after filter changes and during tank cycling
If the barbels start looking shortened, fuzzy, or red at the base, do not just medicate and hope. Clean up the substrate, improve water quality, and swap to sand if needed. Meds without fixing the cause is a loop you'll keep repeating.
One last practical thing: put a sponge prefilter on any intake they can reach. They like to investigate, and a catfish stuck to an intake is a bad day. Same goes for lids - they are not famous jumpers, but startled catfish can surprise you.
Similar Species
Other freshwater peaceful species you might be interested in.
Ajuricaba tetra
Jupiaba ajuricaba
Jupiaba ajuricaba is a South American freshwater characin from the Amazon basin in Brazil (rio Negro, rio Solimões, and rio Tapajós basins). It reaches about 9.5 cm SL and is diagnosed by a narrow dark midlateral stripe, an elongated humeral spot, and an ocellated spot on the upper caudal-fin lobe. Wild specimens have been collected from blackwater forest streams and also oxbow-lake habitats.
Amapa tetra
Hyphessobrycon amapaensis
This is a tiny, super sleek little tetra with a clean red stripe down the side that really pops once its settled in. It does best in a planted, slightly tinted "creek-style" setup and looks way cooler when you keep a proper group so they school and flash that line together. If you can give it soft, slightly acidic water and a calm community, its an easy fish to fall for.
Anteridorsal Homatula loach
Homatula anteridorsalis
This is a benthic Chinese stream loach from Yunnan that lives right down on the bottom in clear, flowing water over gravel and rocks. Think of it as a "river tank" fish - it wants current, oxygen, and lots of surfaces to poke around on for bits of food and algae.
Armoured stickleback
Indostomus paradoxus
This is that goofy little "freshwater seahorse"-looking fish that just kind of perches and scoots around like a tiny armored twig. Its whole vibe is slow, sneaky micropredator - once its settled in, you will catch it stalking microfoods and doing these subtle little posture displays. The big trick is feeding: they do best when you can provide lots of small live foods in a calm, planted tank.
Aroa twig catfish
Farlowella martini
Farlowella martini is one of those unreal-looking stick catfish that just vanishes the moment it parks itself on a branch. It is a super calm, slow-moving grazer that does best in a mature tank with lots of biofilm, gentle flow, and clean, oxygen-rich water - they are not great at competing at feeding time, so you kind of have to look out for them.
Austellus barb
Dawkinsia austellus
Dawkinsia austellus is a freshwater cyprinid endemic to southern India (Western Ghats region). It is an active, shoaling barb best maintained in a group in a spacious, well-filtered aquarium with good oxygenation and regular maintenance.
More to Explore
Discover more freshwater species.
American flagfish
Jordanella floridae
Jordanella floridae is that little Florida native with the red-and-cream striping that really does look like a tiny flag once a male colors up. They graze algae like champs (especially stringy/hair algae), but they have a bit of attitude - give them plants and space so the bossy behavior stays manageable. Bonus: the male guards the eggs and will actively fan them, which is pretty fun to watch.
Aracu-comum
Schizodon vittatus
Schizodon vittatus is a large South American anostomid (family Anostomidae). Reported maximum size is about 35 cm standard length; it is harvested/consumed in parts of Brazil and is not commonly covered by mainstream aquarium husbandry references.
Arrowhead puffer
Pao suvattii
Pao suvattii is that sneaky Mekong puffer that likes to sit low and ambush food, and it has that super recognizable arrow/V pattern on its back. Gorgeous fish with tons of personality, but it is absolutely not a community guy - plan on a solo, species-only setup if you want everybody to stay in one piece.
Banded Borneo hillstream loach
Gastromyzon fasciatus
Gastromyzon fasciatus is one of those super-cool little Borneo hillstream loaches that scoots around rocks like a tiny stingray and parks itself in the current. It really shines in a river-style setup with lots of smooth stones to graze on and high oxygen - they look busy all day and have a neat, banded pattern.
Banded Leporinus
Leporinus fasciatus
Banded Leporinus are those torpedo-shaped, black-and-yellow striped fish that look like they're wearing a little prison outfit-and they stay on the move. They've got a ton of personality and they're awesome to watch cruising and picking at stuff, but they're also the kind of fish that will redecorate your tank and "taste test" anything soft-looking.
Bandi River dwarf cichlid
Wallaceochromis signatus
Wallaceochromis signatus is a rare little West African dwarf cichlid that used to show up in the hobby as Pelvicachromis sp. "Bandi 1" or "Guinea". It is a sand-sifter that loves to dig and claims a cave as its base, and the female usually has a really obvious black tail spot that makes ID pretty straightforward.
Looking for other species?