Sand catlet

Where they come from

Sand catlets are tiny African loach-catfish from sandy stretches of rivers and streams. The species name points to the Wami River in Tanzania, and that lines up with how they act in the tank: they bury in fine sand with just eyes and barbels sticking out, waiting for little critters to drift by.

Setting up their tank

Think river margin with clean, fine sand and steady, gentle flow. They are small, but I would still give a group a 15-20 gallon tank with more floor space than height. Keep the light on the dim side and use a tight lid; they can surprise-jump during lights-out shuffles.

• Substrate: 2-5 cm of fine, rounded silica sand. They must be able to bury completely.
• Flow and oxygen: moderate current with lots of surface movement. A spray bar or small powerhead aimed along the front works well.
• Filtration: oversized filter with a sponge pre-filter on every intake. These fish are tiny and curious.
• Aquascape: open sandy areas plus scattered rounded pebbles, driftwood, and leaf litter. Leave calm pockets out of the main flow.
• Water: 22-26 C (72-79 F), pH 6.2-7.4, soft to mid-hard (2-8 dGH). Keep it clean and stable; they do not forgive neglect.
• Lighting: subdued. Floating plants or tannins help them feel secure.

Maintenance is a little different: I lightly hover the siphon over the sand to lift debris without digging deep. Every week or two I gently rake the top layer with my fingers to prevent compaction and gas pockets. Leaf litter traps biofilm they like to pick at, but do not let it smother the sand. Keep intakes covered, and clean pre-filters often so flow stays strong.

What to feed them

They are crepuscular hunters. You will get the best response by feeding at dusk or 30-60 minutes after lights out. They hunt by scent, so target feeding is your friend.

• Live or frozen: baby brine shrimp, cyclops, daphnia, chopped blackworms, mosquito larvae, small bloodworms.
• Prepared: high-quality micro wafers and fine carnivore pellets that sink fast.
• Occasional: crushed snails or tiny bits of shrimp for variety.

They fill up quickly. I feed small amounts once daily and skip one day a week. If bellies look tight or they start spitting bloodworms, rotate to softer foods like daphnia and baby brine for a bit.

How they behave and who they get along with

Expect a lot of peekaboo at first. In a group they relax: you will see them pop out at dusk to skitter over the sand, then disappear like quicksand ghosts. They are not aggressive, but they are slow eaters and get pushed off food by bolder fish.

• Great choices: species-only setup, tiny lampeyes (Aplocheilichthys/Procatopus), pencilfish, small rasboras, very calm dwarf killifish. Peaceful snails are fine.
• Maybe, with care: shrimp. Adults are usually safe, but they will snack on shrimplets.
• Avoid: anything boisterous or bottom-heavy feeders (loaches, corys, larger tetras, barbs, Synodontis). Also avoid large or nippy fish that patrol the bottom.

Breeding tips

This is still a white whale in the hobby, but you can nudge them. Females bulk up a bit rounder; males stay slimmer. Spawning seems to happen at night, and eggs are likely scattered into the sand with no care given.

• Set up a separate 10-15 gallon with deep fine sand, gentle flow, and lots of oxygen.
• Condition the group on live foods for 2-3 weeks.
• Simulate a rainy season: a series of larger, slightly cooler water changes (2-3 C drop) with soft water and increased flow.
• After a few nights, remove adults so they do not eat eggs or hatchlings.
• Fry are tiny. Start with infusoria/green water, then move to vinegar eels and freshly hatched baby brine once they can take it.

Common problems to watch for

• Barbel wear or skin abrasions from rough substrate. Fix the sand before it turns into infections.
• Low oxygen. If they are gulping at the surface or refusing food, increase surface agitation and flow.
• Slow starvation. They often lose out at mealtime. Target feed after lights out and check body weight weekly.
• Filter mishaps. Cover every intake with sponge. Check gaps around lids; they can wedge themselves out.
• Parasites from import. Stringy white feces, weight loss, or flashing are common flags.
• Fungal tufts on scrapes after shipping. Clean water and mild treatment usually sort it.

Quarantine pays off. I have had good results with praziquantel for tapeworms and levamisole for nematodes, with big water changes between rounds. Feed lightly during treatment and watch for regained appetite and normal burying behavior.