Bumblebee goby (Bumblebee fish)

1) Where they come from

Bumblebee gobies (Brachygobius xanthozonus) come from Southeast Asia, hanging around slow, mucky areas where rivers meet the sea—mangroves, tidal creeks, and brackish backwaters. That “in-between” water is the whole trick with these guys: they’re not really a straight freshwater fish, even if some stores sell them that way.

2) Setting up their tank

Think “small, shallow, and structured.” They’re tiny, but they love having little territories—caves, rock gaps, shells, and piles of wood. A bare tank stresses them out and turns them into grumpy little speed bumps that refuse food.

For brackish, I’ve had the best results using marine salt mix (not aquarium “tonic” salt) and aiming for a low brackish salinity. You don’t need to go crazy—just keep it consistent and measure it with a hydrometer or (better) a refractometer.

• Tank size: 10–20 gallons works well for a small group; bigger is always easier to keep stable
• Salinity: low brackish (roughly SG 1.005–1.010 is a common range people keep them at—pick a number and stick to it)
• Temp: mid-to-high 70s°F (around 24–27°C)
• Substrate: sand is nice because they perch and sift around it
• Flow: gentle to moderate; they’re not river-fish that want to fight a powerhead all day
• Hardscape: lots of little caves/crevices so they can claim spots without constantly bickering

Plants can be hit-or-miss in brackish. Java fern and anubias sometimes tolerate low brackish, and mangrove-style setups look awesome. Even if you skip plants, you can make it feel “alive” with rocks, shells, and some leaf litter (as long as it’s safe and you keep up with maintenance).

3) What to feed them

Bumblebee gobies are picky in a very specific way: they want small, meaty foods that move. A lot of them ignore flakes and pellets, especially when new. Once they recognize you as the food-bringer, they get bold, but you still need the right menu.

• Best staples: frozen bloodworms, frozen brine shrimp, mysis (chopped if needed)
• If they’re being stubborn: live baby brine shrimp, live blackworms, live daphnia
• Sometimes accepted: micro-pellets or gel foods (only after they’re settled and eating well)

Feeding tip that’s helped me a lot: use a feeding dish or a turkey baster to drop food right into their “hangout zone.” They’re perch-and-pounce hunters. If the food blows all over the tank, faster fish will steal it and your gobies will slowly fade.

4) Behavior and tankmates

They’re tiny, cute… and kind of bossy. Bumblebee gobies squabble with each other, especially in tight spaces, but it’s usually more bluffing than real damage if the tank is laid out well. I like keeping them in groups so the “attitude” gets spread out instead of one fish getting singled out.

Tankmates are where people get burned. These gobies are slow eaters and easy to outcompete. And because they’re brackish, your choices narrow fast.

• Good-ish matches: other small brackish fish that aren’t hyper and won’t steal every bite (some people do well with figure-8 puffers, but only in larger setups and you must watch for fin nipping and food competition)
• Often works: species-only bumblebee goby tank (my personal favorite because feeding is simple and everyone gets their share)
• Avoid: big aggressive fish, super fast feeders, and anything that sees tiny gobies as snacks

5) Breeding tips

They can breed in aquariums, and it’s a fun project if you like watching fish do “cave stuff.” Spawning usually happens in a tight cave or tube, and the male guards the eggs. The hard part isn’t getting eggs—it’s raising the fry because they need tiny live foods.

• Give them caves: small snail shells, tight rock caves, short pieces of PVC work great
• Condition with live/frozen foods: bloodworms and live baby brine shrimp go a long way
• If you see a male camping in a cave and chasing others off: check for eggs (but don’t keep shining a light in there all day)
• Fry plan: have infusoria/microworms ready, then baby brine shrimp once they can take it

6) Common problems to watch for

Most bumblebee goby issues come from two things: wrong water (kept freshwater long-term) and not getting enough food. They don’t always crash quickly, which is why people think everything’s fine… until it isn’t.

• Slow starvation: skinny bodies, hollow bellies, acting “fine” but fading over weeks
• Being outcompeted: tankmates eat everything before the gobies even notice it
• Salinity swings: topping off evaporation with saltwater instead of fresh can creep salinity up over time
• Ich/skin issues after purchase: stress + poor conditions at the store can show up a week later
• Internal parasites: refusal to gain weight even when they seem to eat; stringy poop can be a clue

If a new batch won’t eat, I don’t play the waiting game. I start with live baby brine shrimp or live blackworms for a few days to “switch them on,” then transition to frozen. Once they learn the routine, they’re actually pretty consistent little eaters.