Stellate tadpole-goby
Benthophilus stellatus
The Stellate tadpole-goby exhibits a slender, elongated body with a distinctive pattern of star-like spots and a translucent, pale yellow to brownish hue.
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About the Stellate tadpole-goby
This is one of those weird little bottom-huggers from the Black Sea/Azov/Caspian region - big head, narrow tail, and a body covered in tiny bony bumps. It spends its time on mud and sand in cooler water, picking at small invertebrates, and it is way more of a coldwater/brackish oddball than a typical tropical aquarium goby.
Also known as
Quick Facts
Size
13.5 cm
Temperament
Peaceful
Difficulty
Advanced
Min Tank Size
20 gallons
Lifespan
1-2 years
Origin
Eastern Europe and Western Asia (Black Sea, Sea of Azov, and Caspian basins)
Diet
Carnivore/invertivore - small crustaceans, insect larvae, mollusks, and tiny fish; in captivity would take frozen/live foods
Water Parameters
4-20°C
7-8.5
8-25 dGH
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Calculate heater sizeCare Notes
- Give them a footprint tank with lots of bottom space - sand or very fine gravel, scattered smooth rocks, and a few tight caves made from stacked stones or PVC elbows. They are basically a floor fish that wants crevices, not tall water.
- Run it brackish and stable: aim around SG 1.005-1.010 and keep it there with a refractometer (swing-arm hydrometers lie). They hate sudden changes, so pre-mix saltwater and do smaller, frequent water changes.
- Keep it cool-ish and clean: about 64-72F works well, with strong oxygenation and a decent current. If the surface looks still, add more flow because these guys come from well-oxygenated water.
- Feed sinking meaty stuff and target-feed so they actually get it: frozen mysis, chopped krill, bloodworms, blackworms, and small bits of clam/shrimp. They can be shy at first, so use a feeding tube or turkey baster to drop food right in front of them.
- Skip fast midwater pigs and fin-nippers - they will outcompete a stellate tadpole-goby and stress it into hiding. Better tankmates are other calm brackish bottom types that do not bulldoze the same caves; avoid large aggressive gobies/sculpins and anything that will swallow it.
- Cover intakes and any tiny gaps because they love wedging into stupid places and can get pinned by suction. Also watch for scraped bellies if your substrate is sharp - sand saves headaches.
- Breeding is doable if you can keep a bonded pair: give multiple tight caves and expect the male to guard eggs stuck to the roof of a cave. If you see one fish camping a cave and chasing others off, do not rearrange decor or you will reset the whole process.
Compatibility
Good Tankmates
- Other small, peaceful brackish bottom guys that mind their own business - like other tadpole-gobies or small gobies from similar water (just give lots of little hidey-holes so they can spread out)
- Bumblebee gobies (Brachygobius) in lightly brackish setups - they hang around the bottom too, but they are usually chill if you keep them well-fed and not overcrowded
- Small brackish livebearers like mollies (especially short-finned types) - they stay up in the water column and do not hassle a tiny bottom sitter much
- Figure 8 puffers - only if the puffer is unusually mellow and the tank is big with line-of-sight breaks (I have seen it work, but you are rolling the dice with any puffer)
- Brackish halfbeaks (wrestling halfbeaks) - top dwellers, generally ignore bottom fish, and the goby does not compete with them for space
- Knight gobies when the stellate is already established and the tank has lots of caves - it can work in a roomy tank, but watch feeding because the knight goby is a pig
Avoid
- Anything big and bossy like scats or monos - they will outcompete for food and basically bulldoze a little stellate tadpole-goby all day
- Most puffers (green spotted, etc.) and other known fin-nippers - even if they are not trying to eat the goby, they love picking at slow bottom fish
- Fast, aggressive feeders like larger archerfish - the stellate is a slow, sit-and-wait eater and will get starved out
- Big predatory brackish fish (snakeheads, bigger cichlids, big gobies that treat everything as a snack) - if it fits in their mouth, it is on the menu
Where they come from
Stellate tadpole-gobies are little bottom-sitters from the Ponto-Caspian region (think Caspian and Black Sea drainages). They come from brackish, silty places with lots of shell grit, rocks, and muck. If you have ever kept other oddball Ponto-Caspian gobies, the vibe is similar: tough water, cold-to-cool temps, and a fish that would rather scoot than swim.
This is one of those species where the name in shops can be sloppy. Double-check photos and collection origin if you can, because "tadpole goby" gets used for multiple Benthophilus.
Setting up their tank
Think "micro predator on a messy shoreline" and build around that. They spend their time on the bottom, perched and hopping between cover, so floor space matters way more than height.
- Tank size: I would start at 15-20 gallons for a small group, larger if you want tankmates.
- Substrate: fine sand mixed with a bit of shell grit or small rounded gravel. They like to settle into it.
- Hardscape: lots of small rocks, broken up lines of sight, and a few tight caves. I use piles of smooth pebbles with gaps rather than big open caves.
- Flow and oxygen: moderate flow and strong surface agitation. They come from oxygenated, open water edges more than stagnant puddles.
- Filtration: oversize it. They are messy eaters and you will be feeding meaty foods. A canister or a big HOB with sponge prefilter works well.
For brackish, I keep them in low to mid brackish rather than barely-salty. Something around 1.005-1.010 specific gravity has worked for me, with stable hardness and alkaline pH. They do not love swings, especially right after shipping.
Mix your saltwater in a bucket, match temp, and drip it in for top-offs and water changes. Pouring in salty water straight can make quick salinity spikes near the bottom where they sit.
Temperature-wise, cooler is your friend. Mine did best in the mid-to-high 60s F and were still fine around low 70s, but I avoid warm, tropical setups long-term. If your room runs hot in summer, plan for extra aeration and maybe a fan.
What to feed them
They are bite-sized predators that hunt by ambush. If you offer flakes, most will ignore them. The key is meaty foods that land on the bottom and stay there long enough for them to notice.
- Frozen: mysis, chopped krill, chopped clam, chopped prawn, bloodworms (as a treat, not the only food).
- Live (great for new imports): blackworms, live brine shrimp (adult), small river shrimp, amphipods if you culture them.
- Prepared: sinking micro-pellets can work after they are settled, but I treat that as "bonus" not the main diet.
New ones sometimes act like they are "not eating" when they actually are, just slowly. Feed after lights-out with a small flashlight and you will often catch them hunting.
I feed small portions more often, because big chunks foul the water fast in brackish. Watch the substrate around their favorite perches - if food is accumulating there, you are overdoing it.
How they behave and who they get along with
They are grumpy little bottom gobies, but not murder machines. Most of the attitude is territorial posturing and short dashes. The real problem is that they are easy to outcompete and easy to stress.
- Best kept: species-only, or with calm brackish fish that do not live on the bottom.
- Avoid: fast midwater pigs that steal all food, and any bottom dwellers that want the same caves (other gobies, loaches, big shrimp).
- Group vs single: a small group can work if you give lots of rock piles and broken sight lines. In tight tanks, one dominant fish can harass the rest.
They will eat anything that fits in their mouth. Tiny shrimp and very small fish fry are on the menu. Larger Amano-sized shrimp sometimes coexist, but I would not count on it if the goby is hungry and bold.
If you see torn fins or one fish hiding constantly, add more cover or separate. They do not "sort it out" in a bare tank - the weaker fish just wastes away.
Breeding tips
Breeding in home tanks is possible but not something I would call predictable. They are cave spawners in the broad sense: the male will claim a tight spot, coax a female in, and then guard eggs. The hard part is getting a settled, well-fed pair and giving them the right seasonal cues.
- Caves: narrow entrances and tight ceilings. Half shells, small rock crevices, or short PVC elbows hidden under rocks work.
- Conditioning: heavy meaty feeding for a few weeks, but keep water clean with frequent changes.
- Seasonal nudge: slightly cooler period followed by a gradual warm-up can help. Keep salinity steady during this.
If you ever get eggs, the guarding male can be very defensive. I have had better luck leaving the cave in place and moving other fish out, rather than trying to move the cave and eggs.
Common problems to watch for
Most losses with this species happen in the first couple weeks, and it is usually a mix of shipping stress, wrong salinity, and not getting them onto food quickly.
- Not eating: offer live foods, feed after dark, and keep competition low.
- Salinity swings: small tanks and heavy top-off mistakes get people. Mark a fill line and top off with fresh water only (salt stays behind).
- Dirty bottom: leftover meaty food rots fast. Vacuum lightly and often, especially around rock piles.
- Low oxygen: warm water plus brackish plus heavy feeding equals gasping. Add surface agitation and do not skimp on flow.
- Parasites from wild fish: quarantine if you can. Treating in brackish can be trickier, so prevention is easier than meds.
Do not mix them into a random tropical community "just because they are small". Warm temps, constant competition, and soft water is a perfect recipe for a slow decline you will not notice until its too late.
If you keep the water hard, clean, and stable, and you feed like you mean it (without letting the tank get gross), they are hardy little oddballs. The fun is watching them perch like tiny stone gargoyles, then suddenly pounce when a mysis drifts by.
Similar Species
Other brackish peaceful species you might be interested in.
African moony
Monodactylus sebae
This is that shiny, diamond-shaped "mono" that cruises around in a tight pack and looks like a little silver dinner plate with black bars when it's young. The big thing with African moonies is they're euryhaline-so they'll tolerate freshwater as juveniles, but they really shine long-term in brackish (and can be transitioned toward marine as they mature). Give them a big, open tank and a group, and they turn into nonstop, super fun midwater swimmers.
American shadow goby
Quietula y-cauda
This is a little mudflat goby from California down into the Gulf of California that loves hanging tight to the bottom and vanishing into burrows. The neat tell is that sideways Y-shaped blotch right at the base of the tail, plus the row of dark spots along the side. Its whole vibe is brackish estuary life - calm water, soft substrate, lots of hiding holes.
Banded-tail glassy perchlet
Ambassis urotaenia
This is one of those see-through glassy perchlets where you can literally watch the organs shimmer when it turns-super cool in the right lighting. In the wild it hangs around river mouths and mangroves and cruises in groups, so it does best when you keep a little gang of them and give them some open swimming room.
Barbed pipefish
Urocampus nanus
Urocampus nanus is a skinny little pipefish from sheltered seagrass and estuary areas around southern Japan and nearby coasts, where it hangs out down low among eelgrass. The really wild part is the males brood the eggs in a pouch under the tail and give birth to fully formed mini pipefish. Its care is basically "pipefish rules" - calm tank, lots of live/frozen tiny meaty foods, and tankmates that will not outcompete it at feeding time.
Buffon's river-garfish
Zenarchopterus buffonis
This sleek, surface-dwelling halfbeak has a distinct dark stripe along the snout and is typically found at the surface in coastal waters, estuaries, and rivers where it feeds on terrestrial insects. In aquaria it does best with floating/surface foods and a secure cover, and it requires brackish (or marine) conditions long-term. Reproduction is internally fertilized; FishBase lists the species as ovoviviparous.
Cuban cusk-eel
Lucifuga subterranea
This is one of Cuba's weird, wonderful cave brotulas - pale, blind, and built for cruising around in dark cave pools and sinkholes. It is a livebearer (yep, it gives birth to fully formed young), and it hunts small crustaceans in those underground waters.
More to Explore
Discover more brackish species.
Atlantic Mudskipper
Periophthalmus barbarus
This is that wild little amphibious goby that straight-up climbs around on land like it forgot it was a fish. They've got big googly eyes, tons of personality, and they'll perch, hop, and patrol their territory-honestly more like a tiny crabby lizard than a "regular" aquarium fish.
Banded Archerfish
Toxotes jaculatrix
This is the fish that literally spits jets of water to knock insects off branches-watching one "take aim" is unreal. They're super aware of what's going on outside the tank and will even learn to beg and snipe food from the surface once they settle in. Give them height and some open swimming room and they act like little aquatic sharpshooters.
Barred mudskipper
Periophthalmus argentilineatus
This is one of those classic "walks around like it owns the place" mudskippers-big goofy eyes, climbs, hops, and spends a ton of time out on the mud when it's humid. In the wild it lives on intertidal mangrove/nipa mudflats and even shuttles between little pools and open air, hunting worms, insects, and small crustaceans. It's super fun to watch, but it really wants a brackish paludarium setup (not a normal aquarium).
Blotched eelpout
Zoarces gillii
Zoarces gillii is a cold-temperate eelpout from the Northwest Pacific that hugs the bottom over sandy-mud inshore areas and even pushes into estuaries. It's got that long, eel-like body and a sneaky, sit-on-the-bottom predator vibe - very much a cool-water, brackish-to-marine oddball rather than a typical tropical aquarium fish.
Bumblebee goby
Brachygobius doriae
Brachygobius doriae is one of the classic "bumblebee gobies" - tiny, bottom-hugging little characters that perch on rocks and sand and stare at you like they own the place. They're at their best in a calm setup with lots of caves and leaf litter, and they really shine once you get them eating frozen/live foods reliably (they're slow, picky eaters). Also: they're one of the species that gets mislabeled a lot in shops, so it's super common to see them sold under the wrong bumblebee-goby name.
Bumblebee goby (Bumblebee fish)
Brachygobius xanthozonus
This is that tiny little goby with the bold black-and-yellow bands that likes to perch on the bottom and stare back at you like it owns the place. It's happiest in lightly brackish water with lots of little caves and sight-breaks, and it's one of those fish that often refuses flakes-frozen/live meaty foods usually flip the "yes, I will eat" switch.
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