SOUTH AMERICAN CICHLIDS.
Order Perciformes
Family Cichlidae
Subfamily ( Cichlasomatinae )
Genus Mesonauta.
Distinction of adult Mesonauta species by stripes.
Mesonauta acora. Mesonauta egregius. Mesonauta festivus.
Mesonauta guyanae. Mesonauta insignis. Mesonauta mirificus.
Following the revision of the genus Mesonauta in 1991 (Kullander, Silfvergrip), identifying the species of mesonautas kept in aquariums has become problematic. In addition, there is reason to believe that some aquarium mesonautas previously considered M. festivus are interspecific hybrids from the perspective of modern systematics. Taxonomic uncertainty does not affect the methods of their maintenance and breeding in the aquarium, for which all Mesonauta spp. have similar requirements.
— Mesonauta acora [Castelnau, 1855] — Mesonauta acora. Synonym: Chromys acora. Brazil, Tapajós, Araguaia, Xingu, and Tocantins river basins. 15 cm. The main background coloration is silvery-yellow. A broad black stripe extends from the tip of the snout through the eye to the upper rear part of the dorsal fin. This stripe is interrupted 1/3 of the way to the dorsal fin. Under stress, faint dark vertical stripes also appear on the body, including the fourth stripe from the head which is interrupted. A black ocellated spot is located in the upper part of the caudal peduncle. Unpaired fins are slightly spotted.
The male is larger than the female. His dorsal and anal fins are more pointed. They get along well with other peaceful cichlids and representatives of other families. However, keeping them with small characins is undesirable, as they may be perceived as food. It is best to keep them in a group of five or more individuals. Plants with large, tough leaves are preferred.
— Mesonauta egregius [Kullander & Silfvergrip, 1991] — Mesonauta egregius. (English — Orinoco Flag cichlid). Colombia, Orinoco and Meta river basins. 15 cm. The main body colors are silvery-blue and silvery-yellow. The posterior part of the body is brownish.
The oblique stripe characteristic of members of the genus Mesonauta, extending from the tip of the snout through the eye to the upper rear part of the dorsal fin, is absent or weakly expressed as a series of vague dark spots; meanwhile, the 3rd stripe diverges, and the 5th stripe is interrupted, leaving a clear space at mid-height. Under stress, dark vertical stripes also appear on the body, including the third stripe from the head, which is split in two in the lower part. A dark ocellated spot is present in the upper part of the caudal peduncle.
The male is larger than the female. His dorsal and anal fins are more pointed. It is best to keep them in a group of five or more individuals. Predominantly herbivorous species. Soft, slightly acidic water is preferred. They prefer “old” but clean water free of nitrates. Filtration, aeration, and water changes are required. pH 4.8-6.5; T 29°C.
— Mesonauta guyanae [Schindler, 1998] — Mesonauta guyanae. Venezuela, Brazil, Guyana, Rio Negro, Demerara, Essequibo, and Cuyuni river basins. 18 cm. The main background coloration is silvery-gray. A broad black stripe extends from the tip of the snout through the eye to the upper rear part of the dorsal fin. The flanks above this stripe and the back feature a reticulated pattern. A black ocellated spot is located in the upper part of the caudal peduncle. The lower lip and the bottom of the gill covers have a turquoise sheen. This particular feature appears to be the most distinct difference between M. guyanae and other Mesonauta. The male is larger than the female, with more pointed dorsal and anal fins.
An aquarium with high water volume, hiding places, and open swimming areas. It is best to keep them in a group of five or more individuals; they occupy the upper water layers. In nature, they are predominantly “vegetarians.” In the aquarium, they practically do not touch plants, except for the most finely leaved ones (and even then, not always), and eagerly consume any live foods. Eggs are attached to vertical surfaces. Both parents guard the eggs and fry, and unlike many cichlids, the school of fry swims near the surface.
Mesonauta festivus, Mesonauta insignis, Mesonauta mirificus.
Laetacara dorsigera, Laetacara fulvipinnis, Laetacara thayeri. 
Last modified and updated on September 4, 2012.
