Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Achirus lineatus

Lined Sole

Lined Sole, Achirus lineatus Lined Sole, Achirus lineatus
Photos by Andy Rapson


Achirus: Greek, a = without + Greek, cheir = hands

General Notes:

Achirus lineatus is often sold as "fresh water sole" this a poor and misleading name because this is a brackish water species. Ideally they should be kept between SG 1.011 - 1.025 with older adult fish kept in the higher salinity level. They will not live for very long in fresh water.

Keep them either on their own or with other peaceful brackish species such as Scats, Monos, and Archer fish. Small fish like bumble bee gobies may be eaten.

Achirus lineatus is a nocturnal feeder which doesn't compete very well for food so avoid other nocturnal feeders such as some of the shark catfish.

An ideal set up for Achirus lineatus should have subdued lighting and soft sand as a substrate which will allow them to safely bury themselves with just their eyes visible. Aquarium decor isn't important other than from an aesthetic point of view.


In the wild environment Achirus lineatus feeds on worms, crustaceans and small fishes. In captivity their diet should include lots of meaty items such as lance fish, krill, squid, shell fish. Dried food is unlikely to be accepted. The best time to feed them is just after the lights have been switched off, they are nocturnal feeders and they may miss out on being fed if food is provided through the day time only.


Peaceful with fish which are to big to be eaten. But they are easily bullied by nippy fish such as puffers.


There are no distinguishing features between the sexes.


Achirus lineatus has never been bred in captivity. In their natural environment they are thought to breed year round, the fry spend some time swimming as plankton while their left eye migrates to the new top side of the fish before settling to a life on the bottom and they are quite slow growing.

Wild status

The IUCN have not evaluated Achirus lineatus so the health of the wild population is largely unknown. They have a wide range but they are not common. They are not widely collected or fished for although they are caught as by-catch where they are regarded as junk fish.

Additional information

Lined soles are rarely found where the salinity is below 15 parts per thousand (approximately - SG: 1.011). But they have been found in water ranging from 4 - 44 ppt. Despite being called fresh water soles they are almost never found in fresh water.

When cared for properly they are hardy and long lived.

Information at a glance

pH: 7.8 - 8.2
dGH: 8 - 35
Temperature: 22 - 26°C (72 - 80°F)
Lighting: Subdued
Diet: Carnivore
Size: 23cm (9in)
Min tank size: 250 litres
Difficulty level: Difficult
Aquarium type: Community
Swimming level: Bottom

Distribution and habitat

distribution map for Lined Sole, Achirus lineatus

Origin: Western Atlantic: Florida, USA and northern Gulf of Mexico to northern Argentina.

Habitat: Achirus lineatus is found mainly in brackish or hyper-saline lagoons, on sandy-muddy bottoms of estuaries and in the littoral zone


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Pleuronectiformes
Family: Achiridae
Genus: Achirus
Species: A. lineatus (Linnaeus, 1758)

Other common names:
Fresh water sole

Pleuronectes lineatus
Pleuronectes nigricans