South American Bumblebee Catfish

Where they come from

South American bumblebee catfish (Microglanis parahybae) come from Brazil, in the Paraiba do Sul river basin area. Think smaller rivers and streams with leaf litter, roots, and a lot of little nooks where a tiny catfish can vanish all day and come out to hunt at night.

They are one of those fish that look like a chunky, cute oddball at the store... then you get them home and realize they are basically a stealth predator with a paint job.

Setting up their tank

Give them cover first, open space second. If you set up the tank like a typical community tank with a bare bottom and a couple plants, you will almost never see the fish and it will act jumpy. If you give it caves and clutter, it settles in and you will spot it more often.

• Tank size: 20 gallons is workable for one, but 30+ is nicer if you want tankmates or multiples
• Substrate: sand or smooth fine gravel (they spend time on the bottom and around caves)
• Hiding spots: small caves, coconut huts, rock piles with tight gaps, driftwood tangles, leaf litter
• Light: they prefer it dim; floating plants help a lot
• Flow: gentle to moderate; they do not need a river-tank blast
• Filtration: decent mechanical + biological, but avoid creating a jet right at their cave

Water-wise, aim for typical soft-to-medium freshwater community parameters. They handle a range, but they hate sudden swings. Keep nitrates down with regular water changes and do not let food rot under the wood (easy to do with a nocturnal fish).

What to feed them

They are meat-first bottom hunters. If you only feed flakes at the surface, your bumblebee will slowly lose weight while everyone else gets fat. You want foods that sink and smell like food to a catfish.

• Staples: sinking carnivore pellets, quality catfish wafers with high protein
• Frozen: bloodworms, blackworms, brine shrimp, mysis, chopped krill
• Fresh/live (optional): live blackworms, small earthworm pieces (rinse well), occasional gut-loaded insect larvae where legal
• Clean-up, not diet: they will eat leftovers, but do not count on it

Watch their body shape. A healthy Microglanis looks rounded but not bloated, with some "meat" behind the head. If it starts looking pinched or skinny, it is usually getting outcompeted or you are feeding at the wrong time.

How they behave and who they get along with

Most of the time they are shy and secretive, especially during the day. At night they turn into little hunters that cruise the bottom, poke into plants, and ambush anything they can fit in their mouth.

They are not a terror in a community tank, but they are not harmless either. The rule is simple: if a fish is small enough to be swallowed, you are rolling the dice.

• Good tankmates: medium tetras, rasboras, peaceful barbs, larger pencilfish, dwarf cichlids that hold their own, hardy bottom fish that are not bite-sized
• Be careful with: tiny nano fish (neon-sized and smaller), very small shrimp, fry of any kind
• Avoid: aggressive fin nippers that will harass a cave-dweller, big predatory cichlids that will treat it like a snack

You will notice they have stiff pectoral spines. That is their defense. Use a container instead of a net if you can, because they love to snag nets and it turns into a stressful mess for both of you.

Breeding tips

Breeding Microglanis in home aquariums is not common. It happens, but it is one of those "you accidentally did everything right" fish for most hobbyists.

• If you want to try: keep a small group so you have both sexes (sexing them is not straightforward)
• Provide tight caves and tubes; many small catfish like to spawn in enclosed spots
• Condition with heavy feeding on frozen/live foods, then do a few larger cool water changes to mimic rain
• Keep the tank calm at night - they spawn and court when you are not watching

Common problems to watch for

Most issues I see with these are husbandry problems, not mystery diseases. They are hardy once settled, but they do not forgive dirty, low-oxygen water or constant competition for food.

• Starvation/slow wasting: caused by surface feeding, boisterous tankmates, or feeding at the wrong time
• Bloat/constipation: from too much dry food and not enough variety (mix in frozen foods)
• Damaged barbels: rough substrate, sharp decor, or poor water quality
• Hiding nonstop: too much light, not enough cover, or aggressive/overactive tankmates
• Parasites: wild-caught fish can arrive with internal parasites - watch for stringy poop and weight loss despite eating