Bristlenose Plecos Aren't Handled, and They're Genuinely Hard to Catch

A bristlenose pleco is an observation animal, never one you pick up. The handling it does get is catching and moving: out of a shop bag, into a hospital tank, or out of a tank that is being broken down. That is harder than it sounds with this fish, and the reasons are its spines and its habits.

Why a Net Snags a Pleco

A bristlenose has stiff, lockable spines on its pectoral and dorsal fins, a defense it raises when startled. A net chase is what startles it, and raised spines catch easily in ordinary net mesh. A fish that struggles while tangled risks real injury to itself.

Catching One Without a Chase

The better method uses the fish's own habits. A bristlenose spends the day wedged into a cave or under wood, so let it retreat there, then lift the whole cave out with the fish inside. Out in the open, herd it into a cup or a wide plastic container and lift that out. Square mesh planting pots work as a trap for spiny catfish too, since a round one is easier for the fish to dodge. If you must steady one by hand for a moment, hold it gently but firmly with fingers on either side of the pectoral fins instead of grabbing from above.

This is also why a bristlenose is an awkward pick for a tank you may need to break down and rehome. Nocturnal and low to the bottom, it can stay hidden in decor or substrate long after everything else has been netted out, and a quick teardown turns into a hunt for one fish.

Bagging and Moving

Spines puncture bags. Double bag a bristlenose at minimum, and consider three bags sleeved one inside the other. Tape over the pointed corners of the bag so a panicked fish cannot wedge itself into a corner and lock its fins there. Then put the bag in a dark container or wrap it in a towel or newspaper, which calms the fish and holds the temperature. For anything longer than a trip home from the shop, the aquarium transport guide covers oxygen and heat on the road.

At the other end, the float and the net-only transfer are the same as for any freshwater fish, and the stocking and acclimation guide sets them out. The step to change for a bristlenose is the last one: the net that lifts the fish out of the bag is where it snags, so tip it into a cup inside the bag and lift the cup instead.

Nocturnal by Nature

A bristlenose that's invisible all day and active only after the lights go off isn't hiding from a problem. This species is nocturnal, and first-time keepers often worry something is wrong with a fish they never see, when a cave, a gap behind the filter, or the underside of a piece of driftwood is exactly where it's supposed to spend the day.

Territorial Males

Bristlenose plecos are peaceful toward other species, and a corydoras catfish makes a good tankmate since the two forage different parts of the tank. Guppies, platies, mollies, neon tetras and gouramis are good company too, and so are shrimp and snails. A long-finned bristlenose is the exception to watch: keep it away from fin-nippers such as tiger barbs and kissing gouramis. Males are territorial toward each other and toward similarly shaped bottom dwellers, competing over caves, so plan enough hiding spots that no two males are forced to share.

First-Timer Mistakes

• Assuming a fish that's never visible during the day is sick or dead, when it is simply nocturnal.
• Chasing it with a standard net and meeting the spines.
• Carrying it home in a single thin bag.
• Underestimating how hard this species is to catch on short notice, whether for a health check or a full tank breakdown.

The Bristlenose Pleco encyclopedia profile covers the species itself.

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Sources & Further Reading