Blemished razorfish
Iniistius naevus
The Blemished razorfish features a slender, elongated body with a distinctive pattern of dark blotches and a long dorsal fin extending along its back.
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About the Blemished razorfish
A small razor wrasse with that classic knife-edge profile and a pale body marked with dark blotches, it zips over open sand and then vanishes head-first into it the second it feels spooked. It lives on gentle sand slopes in the Eastern Indian Ocean and sleeps buried, so in a tank it really needs a fine, deep sand bed and a tight lid. ([fishbase.se](https://fishbase.se/summary/SpeciesSummary.php?ID=66868&genusname=Iniistius&speciesname=naevus))
Also known as
Quick Facts
Size
13.2 cm SL
Temperament
Semi-aggressive
Difficulty
Intermediate
Min Tank Size
75 gallons
Lifespan
5-8 years
Origin
Eastern Indian Ocean - Andaman Islands
Diet
Carnivore - frozen mysis, enriched brine, chopped seafood; will pick at small crustaceans
Water Parameters
23-27°C
8-8.4
20-30 dGH
Need a heater for this species?
This species needs 23-27°C in a 75 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Give it a 75+ gallon tank with a big open sand zone and a 3-4 inch bed of fine sugar sand; it sleeps and bolts into the sand, and crushed coral will shred its face. Seat rock on the glass so burrowing does not topple your scape.
- Run a tight-fitting lid and guard powerhead intakes; razorfish launch when spooked and can get minced.
- Keep salinity 1.023-1.026, temp 75-80 F, pH 8.1-8.4, and nitrate under 20 ppm; they sulk and stop eating if you swing salinity fast.
- Feed small meaty foods 2-3 times daily - mysis, chopped clam, blackworms, enriched brine - and let some fall to the sand where they hunt.
- Use a feeding tube or turkey baster aimed at the sand to get it eating fast; vitamin-soak early meals to help it bounce back after shipping.
- Tankmates: peaceful to moderate fish are fine (tangs, fairy wrasses, anthias), but skip tiny shrimp and nano gobies, and avoid bruisers like triggers, big Thalassoma/Coris wrasses, and dottybacks.
- If it vanishes, it is probably buried sleeping or hiding; do not go digging, just dim the lights and give it time.
- Quarantine with a bin of fine sand and consider a praziquantel round for flukes; watch for scuffed mouths from shipping and offer softer foods until it heals.
Compatibility
Good Tankmates
- Sturdy tangs like Kole, Tomini, or Yellow - active grazers that ignore the razorfish and are too tough to hassle
- Foxface rabbitfish - calm but big, minds its own business, perfect foil to a semi-aggro razorfish
- Clownfish pairs (ocellaris, percula, even maroons if the tank is roomy) - territorial at their spot but coexist fine
- Hawkfish like longnose or flame - perchers with attitude, not competing for the sand bed
- Fairy and flasher wrasses of similar size - add them first and give swimming space so the razorfish does not single them out
- Squirrelfish or soldierfish - armored night owls that the razorfish will basically ignore
Avoid
- Tiny, shy fish like firefish, dartfish, and small gobies - they get chased, stressed, or even picked off
- Other razorfish or sand-diving wrasses with a similar body shape (Iniistius, Novaculichthys) - turf wars over the sand bed
- Slow specialty feeders like mandarins, scooters, seahorses, and pipefish - outcompeted for food and easily harassed
- Big thugs and predators like triggers, large Thalassoma or Coris wrasses, groupers, and lionfish - they will bully or try to eat it
Where they come from
Blemished razorfish (Iniistius naevus) are sand-diving wrasses from the Indo-Pacific. You see them cruising open sandy flats and gentle reef slopes, then poof - they vanish into the sand the second something spooks them. They live where there is lots of fine sand and scattered rubble, not in tight coral thickets.
Setting up their tank
Think open beach with a few rock islands. They need room to bolt and a safe bed to sleep in.
- Tank size: 75+ gallons for a single fish. Bigger is better for adults.
- Sand bed: 4-6 inches of fine, soft aragonite (sugar size). Skip coarse or sharp substrates - they dive face-first.
- Layout: Open sand up front, rocks/rubble off to the sides. Leave clear runways.
- Lid: Tight-fitting, no gaps. They launch like missiles.
- Flow: Moderate and diffuse. Avoid blasting the sand where they sleep.
- Lighting: Anything you like; they are not picky about light.
- Parameters: 1.024-1.026 SG, 76-79 F, pH 8.0-8.4, low ammonia/nitrite, nitrate under ~20 ppm.
I like to add a deeper sand drift in one back corner. My razorfish picked that as its bedroom and stopped scattering sand everywhere else.
Coarse crushed coral can scrape their belly and face. If you hear a thump and then see a rasped snout, the substrate is usually to blame.
If you quarantine, give them a container of sand. A plastic food tub full of rinsed aragonite works great and keeps sand out of filters. Without a place to bury, they panic, skip meals, and crash.
Powerheads low to the sand can cause cave-ins or sandstorms. Mount them higher and aim across the surface.
What to feed them
They are micro-predators. New arrivals often need movement to trigger a strike. Once settled, they take frozen readily.
- Starter foods: live blackworms, live enriched brine, small live ghost shrimp (quarantine or culture your own if possible).
- Frozen staples: mysis, chopped clam, chopped shrimp, calanus, marine blend cubes, Masstick pasted on a small rock.
- Dry foods: some individuals learn to take quality pellets, but do not count on it.
- Additives: occasional vitamin/garlic soaks help spotty eaters and support recovery from shipping.
Feed small portions 2-3 times daily at first. Kill the pumps for a couple minutes so food settles near them. Target drop a few pieces right in front of their hide. Once they come out confidently, you can switch to normal broadcast feeding.
If yours ignores food, try wiggling a single mysis on tweezers just above the sand, then let it 'escape.' That chase often flips the switch.
How they behave and who they get along with
Expect lots of burying early on. Mine disappeared for whole afternoons the first week, then settled into a routine: out at lights-on, back under the sand at dusk. They startle easily, so avoid sudden room lights or banging the stand.
- Good tankmates: peaceful to moderately bold fish that do not harass sand sleepers - fairy/flasher wrasses, anthias, gobies, small tangs, halichoeres of similar size (watch personalities).
- Use caution: boisterous or territorial fish that own the sand like large wrasses, triggers, big dottybacks. Constant chasing equals a buried, starving razorfish.
- Reef notes: safe with corals, but they will eat small ornamental shrimp, tiny crabs, and sometimes knock over unsecured frags while launching into the sand. Feather dusters are at risk.
Keep one per tank unless you have a very large system and a known pair. Similar-shaped razorfish often scrap hard.
Breeding tips
These are pelagic spawners that rise into the water column at dusk. Like most wrasses, they are likely protogynous, with social cues driving sex change. In home aquariums, there are no reliable breeding reports. You might see dusk display behavior in a big, calm tank, but getting viable eggs and raising larvae is a whole different project that needs specialized plankton rearing gear and space.
Common problems to watch for
- Jumping: they rocket through the smallest gap. Block all holes around hoses, cords, and overflows.
- Sand injuries: scraped snouts from coarse substrate. Swap to fine sand and keep the top layer clean of rubble shells.
- Not eating: too much competition or stress. Feed with the flow off, try live foods, and consider an acclimation box for a few days so they can eat in peace.
- Internal parasites: stringy white feces and weight loss even while eating. Praziquantel and/or metronidazole (per label) in QT usually clears it.
- Flukes: flashing and excess mucus. A freshwater dip can confirm, then treat with praziquantel.
- Power outage panic: they bury and can suffocate in compacted, low-oxygen sand. Good surface agitation and a battery air pump are worth having.
- Copper and sand in QT: if you medicate, keep sand in a removable tub. Test often since some substrates bind meds.
Let the room lights come on 15 minutes before tank lights in the morning, and ramp them down in the evening. That gentle change cuts down on spook-dives and face bumps.
Do not try to dig them up if they bury for a day or two after shipping. That's normal. Poking around just stresses them and can cause injury. Watch from a distance and offer small meals; they usually pop back out once they feel safe.
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