Whitespotted stargazer
Uranoscopus polli
The Whitespotted stargazer features a flattened body, prominent eyes on top of its head, and distinctive white spots against a dark background.
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About the Whitespotted stargazer
Uranoscopus polli is a bottom-dwelling marine stargazer from the eastern Atlantic (West Africa—Sierra Leone to Angola, including Cape Verde and São Tomé & Príncipe). It often buries in sand or mud with only its eyes and mouth exposed and ambushes passing prey, mainly fish. It is not a typical home‑aquarium species, and—as in other Uranoscopus—there is a large opercular/cleithral spine above the pectoral fin that may be venomous, so handle only with appropriate tools.
Quick Facts
Size
35 cm
Temperament
Semi-aggressive
Difficulty
Expert
Min Tank Size
125 gallons
Lifespan
5-10 years
Origin
Eastern Atlantic: Sierra Leone to Angola; also Cape Verde Islands and São Tomé & Príncipe
Diet
Carnivore - live/frozen meaty foods (fish, crustaceans), will ambush smaller fish
Water Parameters
19.2-27.9°C
8-8.4
8-12 dGH
Need a heater for this species?
This species needs 19.2-27.9°C in a 125 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Give it a big, open sand flat (fine sand 2-4 in deep) because it wants to bury with just the eyes and mouth showing - skip sharp crushed coral or it will get scraped up.
- Stable marine numbers matter with this one: 1.024-1.026 SG, 24-26 C (75-79 F), pH 8.1-8.4, and keep nitrate low (aim under ~20 ppm) since buried ambush fish hate dirty, low-oxygen sand beds.
- Run strong filtration and high flow up top, but keep a calmer zone over the sand where it sits; a powerhead blasting the bottom just keeps it exposed and stressed.
- Feeding is all about meaty marine foods: thawed silversides, shrimp, squid, chunks of fish, and vitamin-soaked pieces on tongs; target feed so faster fish do not steal every bite.
- Do not trust it with small fish or shrimp - anything that fits in its mouth is food, and it strikes like a trap; tankmates need to be too big to swallow and not the fin-nippy type.
- Respect the spines: Uranoscopus species have a large cleithral/opercular spine just above the pectoral fin that may be venomous; use a container to move the fish (not a net) and keep hands away from the sand where it is buried.
- Watch for sand-related problems like mouth abrasions and bacterial infections if the substrate is dirty; siphon the surface and do not let food rot in the bed.
- Breeding in home tanks is basically a long shot - sexing is tricky and they do not just spawn because you feel like it, so plan on keeping a single specimen unless you have a serious breeding setup.
Compatibility
Good Tankmates
- Tough-ish midwater fish that mind their own business, like a medium wrasse (Halichoeres type) - they cruise around and usually ignore a buried stargazer
- Damsels and chromis that are quick and street-smart (but not tiny juveniles) - they can dodge a sit-and-wait ambush better than slow fish
- Rabbitfish (foxface) or other larger algae grazers - steady swimmers, not bottom-huggers, and usually too big to be considered food
- Larger tangs (yellow/blue/convict size range, not babies) - they stick to the water column and tend to leave a stargazer alone
- Big, non-predatory angels (like a robust dwarf angel or a medium angel depending on tank size) - theyre assertive enough not to get bullied, and they dont sit on the sand
- Hawkfish can work if theyre not tiny - they perch on rock, not in the sand, and usually dont bother the stargazer (still watch for size and attitude)
Avoid
- Small fish that can fit in its mouth - gobies, small blennies, tiny clownfish, firefish, cardinals - if it looks bite-sized, it eventually becomes a snack
- Other sand sitters and bottom loungers like jawfish, dragonets (mandarins), sand-perching gobies - they hang right in the strike zone
- Aggressive pickers that harass slow fish or go after eyes and faces, like big dottybacks or nasty damsels - stargazers dont like being pestered while buried
- Big predatory ambush guys (lionfish, grouper types, large scorpionfish) - either theyll eat the stargazer or youll end up with a feeding-war and injuries
- Ornamental shrimp and small crabs – stargazers consume fish and crustaceans that fit in their mouths.
Where they come from
Whitespotted stargazers (Uranoscopus polli) are a benthic ambush predator from the eastern Atlantic, showing up around West Africa. They are the classic bury-in-the-sand, eyes-up, wait-and-lunge type of fish. If you like weird, this is peak weird.
They are not a "swimming around the tank" fish. Most days you will see eyes, maybe a mouth, and a little sand mound that moves.
Setting up their tank
Start with a tank that gives them footprint, not height. They spend their life on the bottom. I would not keep one in anything under about 55-75 gallons unless you are very experienced and the scape is built for it.
The whole game is substrate. You want a sand bed deep enough for them to bury comfortably, and you want it to be the right texture so it does not grind them up or trap junk.
- Tank: 55-75g minimum for one, bigger is nicer if you plan tankmates
- Substrate: fine to medium sand, about 2-4 inches deep; avoid sharp crushed coral
- Rockwork: stable and locked in place (they will undermine sand); leave open sand zones
- Flow: moderate overall, but keep a calmer "sand flat" area so they can sit without getting blasted
- Filtration: oversize it; these fish eat meaty foods and the waste adds up fast
- Lighting: whatever fits the rest of the tank; they do not care much, but give them shaded spots
Do not stack rock on top of sand and call it done. A stargazer will dig. Put rock on the glass or on a solid base, then add sand around it.
Keep the water stable like you would for any predator marine tank: steady salinity, solid oxygenation, and low nitrate if you can manage it. They can handle "normal" reef temps, but big swings stress them out. A tight-fitting lid is smart, not because they jump a lot, but because startled fish do dumb things.
Stargazers can have venomous spines and they bite. Plan your tank so you are not reaching into a buried fish. Use tools, not fingers.
What to feed them
They are built to inhale prey. In captivity that usually means chunky marine meaty foods. The trick is getting them onto non-live foods and not letting them turn into a "live feeder only" problem.
- Best staples: silversides, chunks of shrimp, squid, clam, marine fish flesh (varied)
- Good frozen options: krill, mysis (for smaller individuals), blended predator mixes
- Live foods (use sparingly): small saltwater fish or shrimp as a training tool, not a long-term plan
- Avoid: freshwater feeder fish (fatty profile is wrong and can cause long-term issues), oversized meals that bloat them
Target feeding makes life easy. I use long tongs or a feeding stick and present the food right in front of the mouth. Once they learn the routine, they will "pop up" and take it. Feed smaller portions a few times a week rather than one huge meal that sits in the gut.
If a new stargazer ignores frozen, try scenting: rub the food on clam, or offer a live item once, then follow with thawed pieces immediately after. A lot of them switch once they realize the stick means food.
How they behave and who they get along with
They are calm until something fits in their mouth. Then they are lightning. That means "peaceful" is a misleading label. They are not chasing tankmates all day, but any fish or shrimp that can be swallowed is a snack.
- Best tankmates: larger, confident fish that stay midwater and are not bite-sized
- Risky tankmates: gobies, blennies, small wrasses, small tangs, dartfish (anything that rests on the sand or is mouth-sized)
- Inverts: decorative shrimp are usually expensive food; snails/crabs are a mixed bag depending on size and the individual fish
- With other stargazers: not a beginner move; only consider in a big tank with lots of space and similar-sized fish
They like to bury with just the eyes showing. If you keep a super "clean" bare-bottom or coarse substrate setup, they stay stressed and exposed, and you will see more weird breathing and refusal to eat. Give them a real sand flat and they act like themselves.
Any fish that sleeps in the sand or hangs out on the bottom is in the danger zone, even if it is a decent size. Stargazers strike up, and they do it fast.
Breeding tips
Breeding whitespotted stargazers in home aquariums is very uncommon. They are not like clownfish where you can pair them and watch a nest. In the wild they spawn in ways we do not easily replicate, and sexing them is not straightforward.
If you ever see courtship or spawning behavior, document it. Photos, dates, temps, feeding, moonlight schedule - the whole thing. That kind of hobby data is genuinely useful with oddball species like this.
Common problems to watch for
Most issues come down to three things: bad substrate, poor food habits, and injuries from handling or tankmates.
- Refusing food: common after shipping; dim the tank, give it time to bury, and start with scent-heavy foods (clam, shrimp)
- Sand-related sores: coarse or dirty substrate can irritate the belly and fins; keep the sand clean and not too sharp
- Ammonia/nitrite spikes: heavy meaty feeding and big waste load can crash a young system fast
- Bacterial infections after abrasions: watch for redness, swelling, fuzzy patches around the mouth and fin edges
- Parasites from live feeders: quarantining live food is rarely done, which is why I keep live feeding as a last resort
- Stings/bites during maintenance: you will forget where it is buried exactly once
Before you put your hands in the tank, locate the stargazer. If you cannot find it, use a feeding stick to coax it to show its position, or do your work with long tools and slow movements.
Quarantine is worth the hassle with this species. They ship rough, and treating a sick, buried predator in a display is a headache you only want once.
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