#pan sole

Maximum Size: 4" Aggression: Low Temperature: 74 - 82 F pH: 7.5-8.5 Hardness: 15-25 dH Brackish Tolerance: 1.000-1.025, 1.003-1.010 best Minimum Tank Size: 30 gallons Feeding: Frozen and live foods are staple of diet. Brine and Mysis shrimp, pieces of earthworms, chopped shellfish. Not guaranteed to switch to dry foods. Notes: One of the species sold under the moniker of “freshwater soles”, these fish can indeed live in hard, alkaline freshwater that is kept immaculately clean but are more likely to thrive in at least low end brackish conditions. Among the freshwater soles, the Pan Sole is both the smallest and the most elongated of the species offered.

Like other flatfish, Pan Soles typically spend most of the day buried in the substrate with only eyes showing. Though it will attempt to burrow in just about any substrate, sharp ones like gravel or some sand types (like Tahitian Moon Sand, a glass by-product) are likely to scratch them up and can lead to illness. Your best choice is to use something soft like silica sand or sugar fine aragonite. Other tank decor is largely immaterial. Plants, plastic or otherwise, are likely to be uprooted and are best when weighted down.

Non-aggressive fish, Pan Soles are not taken to eating adults of even smaller species like Guppies and thus are fairly safe tankmates for a wide variety of peaceful fish. Though not social animals, they do seem to get along when kept in groups. Nippy fish like puffers should also be avoided as Pan Soles are easy targets (especially their eyes). To reduce competition for food, Pan Soles are best fed at night just after the lights go off.

Sources

Freshwater Soles (family Soleidae and others), Neale Monks

Giving your aquarium some sole: Success with fresh and brackish water flatfish, Neale Monks

Tonguefish (Brachirus panoides), The Aquarium Wiki