Related FAQs:  Flatfishes, Freshwater "Flounders", Flatfish Overview:  Giving your aquarium some sole: Success with fresh and brackish water flatfish by Neale Monks, Pleuronectiform Fishes /The Conscientious Aquarist American Soles, Flatfishes of the Family Achiridae
Bob Fenner

Family Achiridae: Nine genera, twenty-eight species, some fresh, brackish, mostly marine. Characterized by being "right-handed", with dorsal and anal fins from from caudal, right pelvic attached to anal, and lacking pectoral fins. Preoperculum with a superficial groove.

    Previously these fishes were included in the family Soleidae (the Soles), not "flounders" (which have free pelvic fins and possess pectorals.

Range:

    All Western Atlantic, some in freshwater permanently others for long durations.

Species of Interest/Use/Availability to Aquarists:

Achirus achirus (Linnaeus 1758), the Drab Sole. Venezuela to Brazil. To seven inches in length. Occasional import for aquarium use. Hides under substrate most of the time. Brackish, freshwater.

Achirus lineatus (Linnaeus 1758), the Lined Sole. Florida, Gulf of Mexico to northern Argentina. To nine inches long. Brackish,  marine.

Achiropsis nattereri Steindachner 1876, a Freshwater Sole. South America; Amazon Basin. To about nine inches long. Freshwater.

Trinectes maculatus (Achirus fasciatus in older literature) (Lacepede 1803), the Hogchoker, Small Sole. Massachusetts, Gulf of Mexico, to Venezuela. To eight inches in length. Can live in marine, brackish, freshwater. Do better with some salt (spg 1.005-1.010) in their water.

Selection

Environment

Habitat

    Not sharp sand (silicates are out), not multi-colored.

    Covers, they jump!

Behavior

    Mention color change/camouflage, burrowing, reclusive, nocturnal

    Tankmates, non-aggressive, not eager eaters.

Foods/Feeding/Nutrition

    Most need live foods, near them, like tubificid worms. small livebearers, ghost shrimp when larger. Can be trained onto dead meaty foods. Twice a week feedings are fine.

Disease

    Due to thick slime coats, bottom scratching behavior, these fishes tend to be external parasite resistant, though they can get/succumb to ich, velvet... These complaints are easily treated with manipulation of salt content, as the single celled protozoans are not nearly as adaptable to quick changes in salinity.

Bibliography/Further Reading:

Luling, K.H. 1965. The Small Sole, Achirus fasciatus. TFH 5/65.

Starinchuk, Justin. 1988. Freshwater Flounders?!! FAMA 2/88.