Narrowbody handfish

Where they come from

Narrowbody handfish (Pezichthys compressus) are odd little bottom-walkers from temperate southern Australia. They are part of the handfish group - basically anglerfish relatives that use their fins like hands to scoot around instead of swimming much.

Most hobbyists will never see one offered, and for good reason: these are specialist, cold-water, low-stress fish with a very niche set of needs. If you are looking at one, you are already in public-aquarium territory.

Setting up their tank

Think "chilled, calm, and boring" in the best way. A narrowbody handfish does not want a flashy reef with tons of flow and hot lights. It wants cool water, stable parameters, and lots of places to hunker down and hunt.

• Temperature: cold-temperate (aim roughly 50-59F / 10-15C). This usually means a chiller, not a fan.
• Tank size: bigger is easier for stability. I would not do less than 30-40 gallons for one, and more if you can.
• Flow: moderate overall, but create low-flow pockets near the bottom where it actually lives.
• Lighting: subdued. Bright reef lighting tends to stress them and encourages algae growth you will constantly fight in cool systems.
• Substrate: fine sand or very smooth small rubble. Avoid sharp crushed coral - these fish sit and crawl a lot.
• Structure: lots of low caves, overhangs, and "lean-to" rockwork. Keep it stable so nothing shifts when it bumps around.
• Filtration: oversized and quiet. They do better with very steady oxygen and very low nitrogen waste.

I also like to run a mature system with a refugium or some kind of nutrient export because you will be feeding meaty foods. That means leftover bits. In cold water, bacteria and cleanup crews can feel "slower," so you want extra margin.

What to feed them

These are ambush hunters. They do not chase flakes around the water column. You are basically feeding a little sit-and-wait predator that expects prey to come to it.

• Staples: live foods like small shrimp and other appropriate live crustaceans (species depends on local availability and biosecurity).
• Trained foods (best case): thawed mysis, small pieces of prawn/shrimp, chopped clam, or other marine meaty items offered on tongs or a feeding stick.
• Feeding method: target feed near the fish, on the bottom, with flow turned down for a few minutes.
• Frequency: small meals. Many do better with frequent smaller feedings than one big dump.

Watch the belly and overall "fullness" more than a calendar. A handfish that is missing meals will start looking pinched and will spend less time actively hunting. On the flip side, big fatty meals can foul water fast in a chilled tank.

How they behave and who they get along with

They are slow, deliberate, and pretty much glued to the bottom. You will see them "walk" from spot to spot, perch on rock, and do short lunges at prey. If you are expecting a fish that cruises the glass, this is not that.

• Temperament: generally non-aggressive, but they are predators of small crustaceans and tiny fish.
• Tankmates: keep it species-only or with very calm, cold-water compatible fish that will not outcompete them for food.
• Avoid: fast feeders, nippy fish, anything that will perch on them, and anything that will stress them with constant movement.
• Inverts: most small shrimp and crabs will end up as food or will steal food from the handfish. Choose carefully.

They also do poorly with constant rearranging, loud pumps, and high traffic around the tank. If you have a busy family room tank that gets bumped and tapped, you are setting yourself up for stress-related problems.

Breeding tips

Breeding handfish in home setups is not common, and with narrowbody handfish specifically, you are dealing with a fish that should really be in a serious, dedicated program. That said, the general pattern in handfish is demersal eggs (laid on something) with parental attention varying by species.

• Give them egg-laying surfaces: small vertical structures, branching decor, and stable rock faces in low flow.
• Keep a seasonal mindset: slight temperature and photoperiod shifts can be cues in temperate species, but do not swing things fast.
• If you ever see egg masses: protect them from flow and from curious tankmates. Many eggs fail from fungus or being blasted around.
• Plan for tiny live foods if anything hatches: you will need appropriate planktonic prey ready, not after the fact.

Common problems to watch for

Most issues with handfish come from three things: temperature swings, stress, and food (either not enough, or too messy). Catching problems early is the whole game here.

• Starvation: fish looks thin, ignores food, or gets pushed off feeding spots by tankmates.
• Bacterial infections and fin damage: from rough substrate, unstable rockwork, or being sucked onto intakes.
• External parasites: can show as flashing, excess mucus, or rapid breathing. Quarantine is a must if you are bringing in anything new.
• Poor water quality from meaty foods: cloudy water, rising nitrate, film on the surface, cyanobacteria or nuisance algae.
• Heat events: chiller failure or warm-room spikes. Temperate fish can go downhill fast if you creep into tropical temps.

One more practical thing: do not net them if you can avoid it. Use a container to move them. They are awkward in nets, and fin or skin damage is an easy way to invite infection.