Geophagus Megasema

Datasheet

General Description

Geophagus Megasema, a member of the Cichlidae family, is a species that is rare in the aquarium trade. It belongs to the G. surinamensis group and can be identified by specific characteristics such as a large lateral blotch and roundish dark midlateral marking.

Aquarium Setup

For the optimal setup of a tank housing Geophagus Megasema, it is crucial to provide a soft, sandy substrate to facilitate their natural browsing behavior. Coarser materials should be avoided to prevent feeding inhibition or potential internal damage. Dim lighting, driftwood, scattered roots or branches, and one or two potential spawning sites like flattish rocks can be included. Water quality is paramount, requiring over-filtration, regular substantial water changes, and meticulous maintenance to prevent health issues.

Behaviour

Typically peaceful unless breeding, Geophagus Megasema will not prey on fish larger than a few millimeters. They tend to form loose aggregations and exhibit strong grouping instincts, establishing a noticeable dominance hierarchy when kept in groups of 5-8 individuals. However, in smaller numbers, weaker specimens may face excessive antagonism, leading to unsettled behavior in the group.

Feeding and Diet

Being benthophagous by nature, Geophagus Megasema feed by sifting through mouthfuls of substrate for edible items. Their diet includes small aquatic and terrestrial invertebrates, plant material, organic detritus, and sediment. A mix of high-quality prepared foods, live or frozen food items, and a proportion of vegetable matter is essential for their diet to ensure optimal growth rate and condition.

Reproduction & Dimorphism

Geophagus Megasema is a substrate-spawning, biparental mouthbrooder, with courtship involving fin flaring, circling, and head jerking displays. Breeding pairs select a suitable site for spawning, with the female laying eggs and the male fertilizing them. During post-spawning behavior, the male may become aggressive towards the female, but common scenarios involve the female caring for the eggs while the male defends the territory. Mature males are slightly larger with longer fins, while females have a visible ovipositor during spawning.

Habitat and Distribution

Favoring habitats with soft substrates near shores or islands, Geophagus Megasema congregates in areas with scattered rocks, submerged tree roots, and leaf litter. Endemic to the upper Rio Madeira basin in Brazil, this species has been recorded in the Río Mamoré and Río Guaporé drainages in Bolivia and Brazil.

Distribution

Type locality is Rio Guaporé, Mato Grosso, Brazil, with records indicating that Geophagus Megasema is endemic to the upper Rio Madeira basin, including drainages in Bolivia and Brazil.