Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Mesonauta festivus

Flag cichlid

Flag cichlid, Mesonauta festivusFlag cichlid, Mesonauta festivus
Photos by Andy Rapson


Mesonauta: probably from the Greek 'mesos' meaning middle or average, and 'nautes' for sailo (alternatively from Latin 'nauta' or sailor; the name perhaps refers to he position of dorsal fin origin posterior to the pelvic fin which was the author's principal diagnostic character.

General Notes:

Flag cichlids do best in a planted aquarium with a fine substrate. The fish will feel more secure among bunches of plants and tangles of bogwood than in an open aquarium. Flag cichlids will swim in shoals when they aren't breeding and so they can be kept in groups. They are lovers of warm water and ideally need the temp to be kept between 27 - 30°C . They can be kept in a community aquarium with suitable tank mates which aren't to delicate and aren't to aggressive.


Wild flag cichlids feed on algae, aquatic plants, insects, worms and crustaceans. In captivity they are quite unfussy and will accept a wide range of dried and prepared foods. For best results feed them a varied diet and include some fresh food rather than a diet of dried food.


Males are larger and have more pointed fins when adult.


Flag cichlids are fairly easy to breed and once a pair has formed they will with good care spawn on a regular basis without any special treatment. In order to raise a brood a separate aquarium will be required for the flag cichlids alone. They breed in typical cichlid fashion by preparing a territory, cleaning a spawning site which is normally a flat stone or a leaf and then they lay their eggs there. Both parents will guard the brood and will continue cleaning and fanning the eggs to circulate water around them. The eggs normally hatch after about 48 hours. Once hatched the parents may move the brood to a pre dug pit in the sand and they may repeat this process until the fry become free swimming. Once free swimming the fry are big enough to accept micro worms, freshly hatched brine shrimps and commercially prepared powdered dry food.

Wild status

Flag cichlid, Mesonauta festivus has not been evaluated in the wild so the current state of wild population isn't known.

Information at a glance

pH: 6 - 8
dGH: 4 - 6
Temperature: 25 - 34°C (77 - 93°F)
Diet: Omnivore
Size: 8 - 10cm (3 - 4in)
Min tank size: 100 litres
Difficulty level: Intermediate
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Flag cichlid, Mesonauta festivus

Origin: South America: Paraná River basin, in the Paraguay River drainage in Brazil and Paraguay; Amazon River basin, in the Guaporé (Brazil and Bolivia), Madre de Dios (Peru), Mamoré (Bolivia), Jamari and Tapajós (Brazil) River drainages.

Habitat: Rivers, creeks and streams with muddy or sandy substrate and close to heavy vegetation.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Genus: Mesonauta
Species: M. festivus (Heckel, 1840)

Common name:
Flag cichlid

Synonyms: Mesonauta festivum, Mesonauta festiva, Heros festivus