Guinean sole

Where they come from

Guinean soles (Synaptura cadenati) come from West Africa, around Guinea and nearby coastal areas. They live in estuaries and mangrove-ish zones where the water swings between fresh and salty depending on tides and rain. That whole "water never stays the same" vibe explains a lot about why they can be touchy in aquariums.

Setting up their tank

Think of this fish as a shy, sand-buried predator that hates surprises. Give it floor space, stable brackish water, and a substrate it can vanish into without getting scraped up.

• Tank size: I would not keep one in less than a 40 breeder, and bigger is better because footprint matters more than height.
• Substrate: fine sand, a couple inches deep. Avoid sharp gravel - they rub their belly and fins into it constantly.
• Hiding: a few low caves or slabs of rock/wood on the surface, but keep most of the bottom open. They want "open sand with escape routes."
• Filtration: strong and steady. These guys are messy eaters and leftover meaty food can wreck water fast.
• Flow: moderate. You do not need a river, but dead zones in the sand get gross.
• Lighting: not bright. Floating plants or dimmer light helps them settle in.

For salinity, aim for true brackish, not "a pinch of salt." I have had the best luck keeping them in a steady low-to-mid brackish range rather than bouncing it around. Use a refractometer, not a swing-arm hydrometer if you can. Temperature in the mid-70s to low-80s F is a comfortable zone.

What to feed them

They are not algae grazers. They are little sand ambush hunters that want meaty food on the bottom. The hard part is getting new imports to recognize prepared foods before they burn through their reserves.

• Best starters: live blackworms (if you can get them clean), live or frozen brine shrimp (adult), and small live ghost shrimp.
• Staple foods once settled: frozen mysis, chopped krill, chopped shrimp, clam, and high-quality sinking carnivore pellets (only after they are confidently eating).
• Feeding style: target feed after lights are low. Use long tweezers or a feeding tube and put food right in front of their face.
• Frequency: small meals daily at first. Once they are stable and putting on weight, you can back off to 4-5 feedings a week depending on tank temp and size.

How they behave and who they get along with

Most of the time you will see a pair of eyes and a sand outline. They are calm fish, but they are still predators. Anything small enough to fit in their mouth is a snack, especially at night.

• Good tankmates: medium brackish fish that stay midwater and are not fin-nippers (think calmer monos/scats when sized appropriately, larger gobies, some brackish tolerant rainbows depending on your salinity and temp).
• Avoid: aggressive feeders that steal every bite, fin-nippers, and anything tiny (small gobies, shrimp, juvenile fish).
• Bottom competition: limit other bottom hunters. They do better when they do not have to fight for every piece of food on the sand.

They can also startle easily. Sudden tapping, bright lights snapping on, or a big fish charging around can keep them buried and refusing food. A calmer community makes a huge difference.

Breeding tips

Breeding Synaptura cadenati in home tanks is basically a long-shot. Like a lot of soles, they have a complex life cycle, and the larvae are not the kind of thing you casually raise in a community brackish setup. I treat them as a display and behavior fish, not a breeding project.

Common problems to watch for

Most losses I have seen come down to three things: shipping stress plus parasites, starvation because they never really started eating, and skin damage/infection from bad substrate or dirty sand.

• Refusing food: often new imports. Try live foods, dim lights, and target feeding. Do not let tankmates outcompete them.
• Internal parasites: skinny fish with a normal appetite, white/stringy poop, or slow wasting. Quarantine helps a lot with this species.
• Skin sores and fin rot: usually from rough substrate, ammonia spikes, or food rotting in the sand.
• Gill irritation: can be from wrong salinity swings, poor oxygenation, or parasites. Watch breathing rate and how much time it spends with just eyes above the sand.
• Buried food bombs: chunks of shrimp that disappear into the sand and rot. Siphon the feeding area and do smaller portions.

If you take anything from this: stable brackish water, soft sand, quiet tankmates, and a feeding plan that actually gets food to the fish. Once they settle, they are really cool to watch - you just have to meet them on their terms.