Geophagus Brachybranchus

Datasheet

General Description

Geophagus brachybranchus, commonly known as the "black-throated eartheater," is a species within the Cichlidae family that is characterized by dark markings on the preoperculum and a reddish caudal fin with opaque to clear spots. With a maximum size of 14.0cm, this species is rare in the aquarium trade but is more commonly found in Australia under its vernacular name. It belongs to the G. surinamensis group of closely related species and is one of the 13 described members in this group.

Aquarium Setup

To ensure the well-being of G. brachybranchus, it is crucial to provide a soft, sandy substrate allowing for natural browsing behavior. The tank setup should include dim lighting, driftwood, scattered roots or branches, and potentially one or two flat rocks for spawning sites. It is recommended to maintain high water quality through adequate filtration, over-filtering, and regular 50-70% water changes to prevent health issues in these cichlids. Coarse materials like gravel should be avoided as they can inhibit feeding and damage the fish's gill filaments.

Behaviour

G. brachybranchus exhibits peaceful behavior, except during breeding times, when they may display aggression towards weaker specimens. They are known to exist in loose aggregations, displaying strong grouping instincts, particularly among juveniles. When kept in smaller numbers, dominance hierarchies can form, leading to antagonistic behavior towards weaker individuals.

Feeding and Diet

As benthophagous fish, G. brachybranchus feed by sifting mouthfuls of substrate for edible items, ejecting the remains via gill openings. Their diet primarily consists of small aquatic and terrestrial invertebrates, plant material, organic detritus, and sediment. In captivity, a varied diet including high-quality prepared foods, live or frozen options like bloodworms and Artemia, and vegetable matter is essential for their well-being.

Reproduction & Dimorphism

The breeding of G. brachybranchus involves substrate spawning, with both parents participating in mouthbrooding. Sexual dimorphism is not externally visible, except during spawning when the female's ovipositor becomes apparent. Courtship displays include fin flaring and circling, with pairs selecting and defending a spawning site. The female lays eggs, fertilized by the male, and both parents care for the fry once hatched.

Habitat and Distribution

Naturally found in Suriname and Guyana, G. brachybranchus inhabits gently sloping marginal zones in rivers with substrates of sand, fine gravel, and mud. They are often found around shores or islands with scattered rocks and submerged tree elements. These cichlids prefer habitats with varying flow rates and depths and are commonly associated with other fish species like Hyphessobrycon rosaceus and Corydoras spp.