Zonatus sand catlet

Where they come from

Zaireichthys zonatus is one of those little African catfish that slips under most peoples radar. They come from the Congo basin region (DRC area), living in small streams and river edges where the bottom is sand, leaf litter, and bits of wood. They are built for hugging the bottom and scooting through tight spots, not for fighting current in open water.

If you have kept any of the tiny African sand catlets before, the vibe is similar: secretive, tough in the wild, and weirdly delicate in our tanks if you miss the details.

Setting up their tank

Think small footprint, lots of bottom detail, and zero sharp stuff. Mine spent most daylight hours wedged under wood or half-buried in sand with just the face showing. A bare-bottom tank makes them skittish, and gravel can beat up their belly and barbels.

• Tank size: 10-20 gallons works for a small group, but give them floor space more than height
• Substrate: fine sand (smooth, not chunky)
• Hardscape: rounded stones, driftwood, piles of leaf litter, and tight caves (small PVC elbows work too)
• Plants: not required, but floating plants help them relax under brighter lights
• Flow: moderate is fine, but avoid blasting the bottom where they sit

Water wise, aim for clean and steady rather than chasing a magic number. Soft to moderately hard is usually fine, slightly acidic to neutral is a safe target, and warm-ish temps (mid-70s F) keep them active. What they hate is stale water and sudden swings.

Filtration should be gentle but effective. I like a sponge filter plus a small hang-on-back or canister with a prefilter sponge on the intake. The prefilter matters because curious little catlets will investigate intakes, and they are not strong swimmers.

What to feed them

These are bottom predators and scavengers, but they do best when you feed like they are micro-hunters. Mine took prepared foods eventually, but frozen and live got them eating confidently fast.

• Go-to foods: frozen bloodworms, blackworms (live if you can), chopped earthworms, daphnia, brine shrimp
• Prepared: sinking micro pellets, soft gel foods, and quality wafers (only after they are settled)
• Schedule: small portions after lights dim, 4-6 times a week

If you keep them with faster fish, target feed. I use long tweezers or a pipette to drop food right at their cave entrances. Otherwise the midwater fish will Hoover everything and the catlets slowly fade.

How they behave and who they get along with

They are calm and secretive. Most of the time they are just parked, then suddenly they do a little dart-and-pounce routine on food. In a group they are more confident, but they can be a bit pushy about prime hiding spots.

• Good tankmates: small, peaceful tetras, rasboras, calm barbs, small African characins, dwarf cichlids that are not hyper-territorial
• Avoid: fin nippers, boisterous bottom fish (large Corydoras, big loaches), aggressive cichlids, anything that sees them as food
• Best kept: in a small group if you can provide enough caves and food

They are not a showpiece fish, honestly. You keep them because you like the subtle stuff: little whiskers working the sand, the banded pattern flashing as they turn, and the nighttime activity.

Breeding tips

Breeding is possible, but it is not the easiest project. If you want a real shot, treat it like a dedicated species tank and play the long game. Condition them with live and frozen foods for a few weeks, then do a series of cooler water changes to mimic rainy-season pulses.

• Set up: lots of tight caves and crevices, leaf litter, dim lighting
• Trigger: heavier feeding + frequent partial water changes (slightly cooler)
• Spawning sites: usually inside caves or under wood, where eggs are protected

Fry (if you get them) need tiny live foods early. Microworms, baby brine, and small daphnia are your friends. Keep the bottom clean but do not over-vacuum - you can suck up fry without realizing it.

Common problems to watch for

Most issues I have seen come down to three things: dirty substrate, not enough food getting to them, and stress from tankmates or lack of cover.

• Barbel erosion: usually from sharp gravel, filthy sand, or chronic high nitrates
• Skinny fish that never bulks up: food competition or feeding at the wrong time of day
• Hiding nonstop and refusing food: too bright, too exposed, or too much traffic in the tank
• Ich and other parasites: often show up after shipping stress, especially in newly imported fish
• Sudden deaths: ammonia/nitrite spikes, or oxygen issues in warm tanks at night

If you want one simple habit that pays off: stir and lightly vacuum the top layer of sand during water changes, especially around caves where waste collects. These guys live on the bottom, so whatever settles down there is what they live in.