Rajagopalan's razorfish

Where they come from

Rajagopalan's razorfish is a sand-diving wrasse from clear, shallow Indian Ocean reefs, usually over clean, open sand with scattered rubble and bits of seagrass. Think gentle surf zones and sandy flats where they can dart and disappear in a heartbeat.

Setting up their tank

Give them sand first, everything else second. They live in it, sleep in it, and dive into it when spooked. No sand, no razorfish.

• Tank size: 75+ gallons for a single fish. They use floor space more than height.
• Sand bed: 3-5 inches of fine, soft sand (0.5-1 mm grain). Coarse sand or crushed coral will scrape them up.
• Aquascape: Open sandy runway with a few rock islands. Leave a big patch of unobstructed sand at the front.
• Flow and light: Moderate flow with calmer zones near the sand. Lighting can be reef-bright or modest; they do not need intense light.
• Lid: Tight, snug, escape-proof. These fish launch like missiles during spooks or dusk.
• Mature system: Add them to a stable, established tank (6+ months) so the sandbed has microfauna. They settle faster and pick naturally.

Acclimation goes best with the lights dim. Use a specimen box or clear container to release them right over the sand. Avoid nets; their scales and jaws snag easily. A wide cup is safer.

What to feed them

Wild razorfish hunt tiny crustaceans and worms. New arrivals rarely recognize pellets. Plan on meaty, moving foods and patience.

• Starter foods: Live blackworms, live pods, enriched adult brine (as a bridge), frozen mysis (small grade), Calanus, finely chopped clam or shrimp, fish eggs (Nutramar Ova works wonders).
• Routine: 2-4 small feedings spread through the day at first. They have small stomachs and spook mid-meal.
• Targeting: Use a feeding tube or baster and drop food just up-current of their favorite sand patch. They key in on falling food.
• Transition: Mix a few high-quality micro-pellets with frozen once they are eating well. Some will take them, some never do.

How they behave and who they get along with

Skittish, fast, and very sand-centric. They spend bursts of time cruising low over the bottom, then vanish like a magic trick. Expect them to bury at the slightest surprise, including your shadow.

• Best tankmates: Peaceful to moderately peaceful fish that ignore the sand zone - chromis, dartfish, jawfish, small fairy/flasher wrasses that are not bullies, peaceful gobies.
• Questionable: Other sand specialists (goatfish, some wrasses) that compete for the same food lane.
• Avoid: Aggressive wrasses, triggers, large hawkfish, dottybacks, and anything that patrols the sand hard. Boisterous tanks keep them buried.
• Inverts: They will snack on tiny crustaceans. Small ornamental shrimp are at risk; larger cleaner shrimp sometimes coexist but it is a gamble. Snails are usually fine.

Keep one per tank unless you have a very large footprint and can add a confirmed pair at the same time. Lone individuals settle better and spend more time out.

Breeding

Like other wrasses, they are protogynous and spawn in the water column at dusk. Sex change and pairing happen in the wild, but home breeding has not been pulled off in hobby tanks. If you ever keep a pair, give them a huge sand flat and low-stress neighbors, and watch the dusk dance. That is about as far as it goes for us.

Common problems to watch for

• Refusal to eat: The big hurdle. Start with movement-heavy or live foods and feed small portions often. Keep traffic down around the tank the first week.
• Injuries from substrate: Coarse sand scrapes their face and flanks during dives. Fine sand solves 90% of this.
• Jumping: Any spook can send them airborne. Check every gap in the lid, including around cables.
• Shipping stress and parasites: They are prone to velvet/ich after import. Quarantine with a container of fine sand so they can bury. Prazipro for flukes is usually well-tolerated; copper can be used with monitoring.
• Hiding all day: Often means bullying, too much commotion, or overly bright, open tanks without a calm zone. Add cover islands and dial back foot traffic for a week.
• Sand storms: Very fine sugar sand can blow around with their dives and your flow. Aim powerheads higher and keep the calm zone near the front.