Taxonomy & naming
The twoband cichlid was described by the Austrian ichthyologist Franz Steindachner in 1864 as Heros bifasciatus, on a single specimen (the unique holotype, NMW 74138) labelled simply 'Mexico'. As with the rest of the Middle American 'Cichlasoma' assemblage, it spent generations in that catch-all genus and was later moved through Paraneetroplus before settling in Vieja, where the Catalog of Fishes lists it as valid (Vieja bifasciata). The epithet — 'two-banded' — refers to the dark markings on its flanks. The species sits in the Neotropical subfamily Cichlinae among the heroine cichlids, and the modern herichthyin revision (McMahan et al. 2015) and subsequent checklists retain it in Vieja. Because the original description rested on imprecise locality data, the species' exact range was clarified only later through field work across the Usumacinta and adjacent lowland systems; it is closely allied to the other large 'quetzal-type' Vieja of the region and has at times been confused with them in the trade.
Morphology
Vieja bifasciata is a tall, stout, strongly compressed cichlid; FishBase gives a maximum of about 12 in total length, placing it among the larger species in the genus, and big aquarium males develop a steep forehead and a pronounced nuchal hump. The fish takes its name from dark banding across the body, but its appeal lies in the colour conditioned adults acquire: the ground tone shifts from olive-grey to a pearly turquoise or blue-green, and the head, throat and breast can flush pink, red or coppery, set off by iridescent spangling on the flanks and a dark spot at the base of the tail. Juveniles and subadults are plainer and more uniformly silvery, the bands and colour sharpening with maturity and spawning condition. Sexual dimorphism follows the genus pattern: males grow larger and carry the heavier forehead and hump, ripe females are deeper-bodied; outside breeding condition the sexes are not easily separated.
Habitat
The twoband cichlid is native to the Atlantic (Caribbean) slope of southern Mexico and northern Guatemala, centred on the Usumacinta drainage and adjacent lowland systems; the IUCN assessment records it from Guatemala and the Mexican states of Tabasco, Oaxaca and Chiapas, and field studies document it in lowland rivers of the Lacandon region such as the Tzendales within the Montes Azules Biosphere Reserve. It is a fish of warm, slow, low-gradient water: the calm reaches of lakes, lagoons, oxbows and the sluggish lower and middle valleys of rivers, over soft mud and sand among submerged wood. The IUCN account gives a shallow depth range of about 0–7 ft, consistent with a fish of quiet shoreline and floodplain water. In-situ and aquarium-derived chemistry point to warm, near-neutral to alkaline, moderately hard conditions, in keeping with the calcareous lowland karst country of the Usumacinta basin.
Feeding
Vieja bifasciata is a large omnivore with the strong herbivorous and detritivorous bias characteristic of its genus. FishBase notes it feeding mainly on bottom detritus and vegetable matter in the calm waters of lakes, lagoons and lower river valleys. It works the soft bottom and submerged wood for plant material, algae, detritus, fallen seeds and fruit and the small invertebrates living among them, using robust jaws suited to tearing and grazing vegetation rather than pursuing prey. In the riverine and lagoon community it functions as a large-bodied grazer and processor of plant detritus rather than a predator, though like all big cichlids it takes animal food opportunistically.
Mating
The species is a monogamous, biparental substrate spawner that becomes territorial as a pair forms. Outside breeding it is reasonably tolerant for so large a cichlid, but a settled pair claims and defends a territory around a chosen spawning surface, and — as throughout the genus — pairing can be combative, with a male liable to harass an unready female, so a well-matched pair in adequate space is important. Courtship follows the heroine pattern of lateral displays, jaw-locking 'wrestling', quivering and the joint cleaning and inspection of a flat hard surface, accompanied by the intensifying of body colour and the female's increasing girth as she ripens.
Breeding
Vieja bifasciata is a biparental, open substrate spawner. The pair cleans a flat hard surface and the female lays her eggs on it in the open, after which both parents share guarding and fanning; after hatching the wrigglers are typically moved to pits excavated in the substrate and the free-swimming fry are led about and defended fiercely by both parents. Precise wild fecundity figures are not well documented for the species, but the genus typically produces several hundred fry per spawning, and large females of this comparatively big cichlid can be expected toward the upper end of that range. In aquaria it spawns in the standard biparental manner once a compatible pair, a flat spawning site and a digging substrate are provided; as with the rest of Vieja, the practical challenge is managing the pair's spawning aggression rather than any difficulty in obtaining eggs.
In the aquarium
Vieja bifasciata is a robust, colourful large Central American cichlid kept by enthusiasts of the group but only intermittently available in the general trade. At an adult size around 12 in it needs a large tank: a footprint of roughly 180 × 23.5 in (about 120 US gal) is a sensible minimum for a single fish or a settled pair, with more space advisable if other large fish share the aquarium. Water chemistry is undemanding within the species' natural envelope — a near-neutral to mildly alkaline pH (about 7.0–8.0), moderate hardness and a temperature of roughly 77–84 °F suit it well. As a big, messy feeder it needs generous filtration and substantial regular water changes, but not strong current; aim returns to break the surface for gas exchange.
Use a sand or fine substrate, since the fish digs, and furnish the tank with sturdy rockwork, roots and driftwood that provide cover and break up sightlines; décor must be stable, as an adult rearranges it. Rooted plants are largely futile with Vieja — they uproot and eat vegetation — so greenery is best treated as food or kept to tough, potted or floating species. Diet should respect the species' plant bias: spirulina and other green foods, blanched vegetables and quality vegetable-based pellets as the base, with frozen or live invertebrates as supplements rather than the staple; overfeeding rich protein is a common cause of digestive trouble and head-and-lateral-line erosion in big Vieja.
Temperament is robust but manageable. Outside breeding the species is relatively even-tempered for its size and combines well with other large, sturdy Central American cichlids and big catfish or characins able to hold their own; nothing small enough to be eaten is safe. Aggression rises sharply at spawning, when a guarding pair can dominate even a large aquarium, so ample space, broken sightlines and the readiness to separate fish are the standard safeguards. The usual keeper mistakes are underestimating the adult size, overstocking and feeding too richly rather than any fussiness in the fish.
Conservation
The IUCN Red List assesses Vieja bifasciata as Data Deficient (assessed 24 September 2018 by Maiz-Tome & Lyons, published 2019), with the population trend recorded as unknown. The Data Deficient listing reflects genuine gaps in knowledge of the species' distribution, abundance and biology rather than any documented decline: it is recorded across the Usumacinta lowlands of southern Mexico and northern Guatemala, including within protected areas such as the Montes Azules Biosphere Reserve, but the published information is too thin to support a threat-based category. It carries no CITES listing and is harmless to humans. The broader pressures on its lowland habitat are the familiar ones for the region — deforestation, pollution, water extraction, altered river flow and the spread of introduced tilapia — and the honest position is that, until better surveyed, the species' status simply cannot be judged; its evident adaptability and reasonably wide range, however, suggest it is not among the more imperilled members of the genus.