Bandfin scorpionfish

Where they come from

Bandfin scorpionfish show up across the Indo-Pacific, hanging around rubble patches and coral edges from shallow surge zones down to moderate depths. They are classic sit-and-wait ambush hunters that melt into the background. You will spot the namesake banding in the fins if the light hits just right, but most of the time you will swear you are staring at a rock.

Tank setup

For a single bandfin, I would not go smaller than 30-40 gallons. If you want to mix it with other slow predators, think 55 gallons and up. They are not active swimmers, but they do appreciate room to pick a perch away from flow.

• Aquascape: Piles of porous rock with ledges, a few caves, and a patch of open sand or rubble where it can park and watch. Keep some shaded spots.
• Substrate: Fine sand or small rubble. Avoid sharp rock piles that can snag fins.
• Flow: Moderate with slack areas. They hate blasting flow right on their perch.
• Lighting: Low to moderate. Too much light and they hide constantly.
• Filtration: Predator bio-load is real. Oversize your skimmer, keep mechanical filtration clean, and plan regular water changes.
• Parameters: 1.025 salinity, 24-26 C (75-79 F), pH 8.1-8.4, nitrate under 20 ppm. Stability beats chasing numbers.
• Lid and guards: They do not jump often, but startled fish do weird things. Cover intakes and powerheads so they cannot sit on a spinning prop.
• Handling: Move with a specimen container or jug, never a net. Nets snag spines and skin.

Quarantine helps a ton with feeding and observation. I use a simple bare-bottom QT with a chunk of PVC and a dim light. Drip acclimate, lights off the first day, and offer food at dusk.

What to feed them

They are ambush predators that hunt crustaceans and small fish. Getting them to take non-live food can be the project. Here is what has worked for me:

• Starter live foods: Gut-loaded ghost shrimp or salt-acclimated mollies to wake up the feeding response. Do this short term only.
• Weaning: Use a feeding stick or long tongs. Wiggle thawed pieces like prawn, silversides, sand eel, squid, or clam so they look alive. Aim near the mouth and move like prey.
• Variety and enrichment: Rotate items and soak in a vitamin/HUFA supplement a few times a week. Avoid only-feeding silversides long term.
• Schedule: Juveniles every other day in small portions. Adults 2-3 times per week. A slight belly bulge is enough. They store energy easily.
• Avoid: Feeder goldfish or rosy reds. They are disease-prone and high in thiaminase.

How they behave and who they get along with

Think quiet and calculated. They spend most of the day perched, then perk up at feeding time or in the evening. They will inhale anything that fits in the mouth, and that mouth is bigger than it looks.

• Good tankmates: Larger, calm fish that do not nip, like bigger tangs or a foxface, or other similarly sized scorpionfish in a roomy tank with separate perches.
• Use caution: Lionfish and other slow predators are fine if sizes are mismatched so nobody fits in anyone's mouth. Watch for food competition.
• Avoid: Triggers, puffers, big wrasses, and nippy angels. They pick at fins and can stress or injure scorpionfish. Shrimp and small crabs are snacks.
• With their own kind: Best kept one per tank unless you have space and line-of-sight breaks. Introduce at the same time and feed well to curb squabbles.

Breeding

Not something you will likely see at home. Scorpionfish are broadcast spawners, usually at dusk, releasing buoyant egg masses that drift. Sexing them visually is unreliable, and raising pelagic larvae needs specialized setup. If you ever see a gelatinous egg raft near the surface after lights out, you probably witnessed a spawn, but getting babies past first feeds is a serious project.

Common problems to watch for

• Feeding strikes: Common after a move. Keep stress low, offer at dusk, try live ghost shrimp briefly, then switch back to thawed on a stick.
• Harassment: Frayed fin edges or constant hiding usually means a nippy tankmate. Remove the bully or the scorpionfish will go downhill.
• Injuries and infections: Scrapes from rock or netting can get infected. Have a hospital tank ready and a broad-spectrum antibiotic on hand.
• Parasites: Flukes and external parasites show up as flashing or rapid breathing. Praziquantel is a good first step in QT.
• Water quality: Lazy fish are messy fish. Rising nitrate and phosphate lead to bacterial issues. Keep up with export and do not overfeed.
• Equipment hazards: They like to perch on anything. Guard pump intakes and powerheads so they cannot sit on the prop or get pinned.