Pictus catfish

Quick facts

Adult size

12 cm

Lifespan

can live up to 10 years; captive average 6-8 years

Tank zone

bottom

Temperament

peaceful

Difficulty

beginner

Schooling

recommended 4+ (critical minimum 3, thrives at 6+)

Typically wild-caught

yes - acclimate slowly

Water parameters

Temperature

22–28°C

pH

6.0 to 7.5

Hardness

2 to 15 dGH

Tank requirements

Minimum volume

200 L

Minimum length

120 cm

Flow

moderate

Lighting

low

Substrate

sand

Hiding spots

needed

Open swimming room

needed

Feeding

Diet: omnivore, feeds primarily at the bottom.

Unfussy and food-motivated. Sinking pellets and wafers form the staple diet. Frozen bloodworm, brine shrimp, and mysis shrimp are accepted eagerly. Live blackworms trigger a strong feeding response and are worth offering occasionally. The long barbels are taste and touch organs; the fish explores the entire substrate surface methodically at feeding time, vacuuming up anything edible. Despite being labeled nocturnal, most captive pictus learn to feed in daylight within a few weeks of settling in. Feed once daily, slightly after lights-on or just before lights-out. Overfeeding is easy because they eat fast and beg convincingly. Sand substrate is preferred because it protects the barbels; coarse gravel abrades them over time and can lead to bacterial infection at the base.

Nocturnal feeder; drop food after lights out so it can eat without competition.

Compatibility

• Peaceful toward same-sized fish but a capable predator of small species. That mouth is wider than it looks. Neons, ember tetras, chili rasboras, and any shrimp are food items. Minimum tankmate size: 4 cm body length, which rules out most nano fish.
• Works well with medium community species: larger tetras (black skirt, congo), rainbowfish, barbs, and other catfish. Corydoras make natural companions since they share substrate level but are too stocky to be swallowed.
• Sharp pectoral fin spines that lock into an erect position when the fish is startled or netted. The spines are mildly venomous. A sting feels like a wasp sting and throbs for a few hours. Never net a pictus with a soft mesh net; the spines tangle and you'll injure the fish trying to free it. Always use a rigid container or cup to move them.
• Social. Single specimens hide constantly and feed poorly. Groups of 4-6 settle in faster, show more natural behavior, and come out of hiding during the day. Two is worse than one because they compete for the single best hiding spot.

Habitat

Native to warm, flowing rivers in the Amazon and Orinoco basins, over sandy and muddy substrates with submerged wood and leaf litter. Found across Colombia, Peru, Brazil, and Venezuela. The species occurs in two geographic forms that occasionally show up in the trade: a smaller Colombian form with large, well-defined spots, and a larger Peruvian form with finer spotting. Both are sold as "pictus catfish" without distinction. Wild populations inhabit channels with moderate current, which is reflected in the fish's need for good flow and oxygenation in the tank. The metallic silver body catches light in a way that makes them visible even in dim tanks. They're one of the most recognizable catfish in the hobby, sold in nearly every fish store that carries tropicals. All specimens are wild-caught from South America; there's no commercial breeding operation for this species.

Breeding

Not bred in home aquariums. Every pictus catfish in the trade is wild-caught from river systems in the Amazon and Orinoco basins. The specific triggers for spawning are unknown, but likely involve seasonal flood cycles, large migrations, and environmental cues that can't be replicated in a glass box. Sexing is unreliable; gravid females may appear slightly rounder when full of eggs, but that's about it. Attempts at hormone-induced spawning in commercial facilities have reportedly occurred in Southeast Asia but details are scarce and no captive-bred stock has reached the general hobby market.

Common problems

The pectoral spine issue deserves emphasis because it catches every new keeper off guard. When stressed or handled, pictus catfish flare and lock their pectoral spines outward. These spines are serrated and mildly venomous. Consequences: they get tangled in nets (use a container, always), they can puncture transport bags (double-bag with a rigid inner container), and they can sting your hand if you're reaching into the tank. The sting isn't dangerous but it hurts. Barbel damage from rough substrates is the other common problem. Gravel substrates wear down the barbels over months; shortened or eroded barbels impair the fish's ability to find food because they navigate and hunt almost entirely by touch. Sand substrate prevents this. Ich is common in newly imported wild-caught specimens. Pictus catfish are scale-covered (despite looking smooth), so standard ich treatment at half dose is safer than the full dose used for scaled fish. A lot of keepers underestimate tank size requirements. Pictus are restless swimmers that cruise the entire tank at night. A 120 cm tank is the minimum for a group, and even then they'll use every centimeter.

Bioload

Bioload coefficient: 5.5 (12 cm active catfish, moderate waste production. swims constantly, needs volume for activity more than bioload).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size