Imparfinis cochabambae

Where they come from

Imparfinis cochabambae is a small three-barbeled catfish from the foothill streams of Bolivia (think Cochabamba region) and nearby drainages. They hug the bottom in clear, fast water with rocks, wood, and leaf litter. Nights are for hunting; days are for hiding in crevices.

Setting up their tank

Give them floor space and flow. A 30-40 gallon long works well for a small group. They are escape artists, so use a tight lid with all gaps covered.

• Substrate: fine sand with rounded pebbles and cobbles on top. Avoid sharp gravel that can wreck barbels.
• Hardscape: piles of stones, snug caves, driftwood branches, and some leaf litter for cover.
• Filtration and flow: strong, oxygen-rich. A canister with a spray bar plus a powerhead works. Pre-filter sponges save whiskers.
• Lighting: dim. Floating plants over the quiet end help them feel braver.
• Parameters: 68-75 F (20-24 C), pH 6.2-7.4, soft to moderate hardness (2-10 dGH). Keep nitrate low.

What to feed them

They are nocturnal micro-predators. Think small meaty foods that sink. Feed after lights out or just as the room goes dark.

• Frozen or live: bloodworms, blackworms, mosquito larvae, daphnia, mysis, finely chopped earthworm.
• Dry: quality sinking carnivore pellets or insect-based sticks. Soak them so they drop straight to the bottom.
• Gel foods: Repashy-style bottom formulas work if you wedge pieces under wood or stones.
• Frequency: small portions nightly or every other night. Skip a night each week to keep waistlines in check.

How they behave and who they get along with

By day they keep a low profile. At dusk they get curious and start cruising the bottom. They are not bullies, but they will snack on tiny fish or shrimp that fit in their mouth.

• Better in small groups (3-6). They do not school, but seeing others around makes them bolder.
• Peaceful midwater companions that handle flow: sturdy tetras from cooler water, smaller rainbowfish on the cooler end, and similar-sized characins.
• Bottom neighbors: small loricariids (like Chaetostoma and Rineloricaria) and cooler Corydoras species can work if everyone gets fed.
• Avoid: big or nippy fish, delicate nano fish, dwarf shrimp, and anything that will outcompete them at feeding time.

Breeding tips

This species is rarely bred in home tanks, but they likely use crevices under stones during the rainy season. I have not spawned them, though I have seen courting behavior after cool, heavy water changes and a burst of live foods.

• Set up a dedicated tank with strong flow, smooth flat stones, snug caves, and leaf litter.
• Condition a pair or small group on live and frozen foods.
• Trigger: several cooler water changes in a week, slightly softer water, and dim light.
• If you spot eggs under a stone, move the whole stone to a hatching box with the same water and a gentle airstone.
• Larvae are tiny. Start with microworms or vinegar eels, then switch to newly hatched brine shrimp once they can handle it.

Common problems to watch for

They are not hard if you give them clean, oxygen-rich water and food they can actually find. Most hiccups come from lack of flow or getting outcompeted.

• Low oxygen: fast breathing, hanging in the filter outflow, or sudden lethargy. Add air and increase surface agitation.
• New tank syndrome: any ammonia or nitrite is a no-go. Seed media and be patient.
• Damaged barbels: rough gravel or dirty substrate. Use sand and vacuum around rock piles.
• Feeding stress: daytime feeders steal everything. Feed after dark and target-deliver food.
• Parasites on wild-caught fish: quarantine 4 weeks. Deworm with levamisole and praziquantel if needed.
• Scrapes and fungus: keep water clean, remove sharp decor, and treat gently. Scaleless catfish are sensitive to harsh meds.