Classification:
Order: Perciformes
Family: Cichlidae
Distribution:
Native to river systems of eastern and southern Brazil and Uruguay draining into the Atlantic Ocean with type locality given as ‘Rio de Janeiro Bay, Brazil’.
Habitat:
Most often recorded in coastal drainages and the lower reaches of rivers, and some populations inhabit coastal lagoons with permanent or temporary connections to the ocean so have evolved a degree of salt tolerance. It’s perhaps best described as a habitat generalist since it’s been recorded from biotopes with varying levels of water movement and turbidity, from fast-flowing to stagnant and crystal clear to impenetrable, respectively, and different substrate-types.
Maximum Standard Length:
Males to 200 – 250mm; females 130 – 150mm.
Aquarium Size:
Minimum base dimensions of 150 x 45cm or equivalent are required for long-term care. It is advised to find a filter which has a water flow between 4-5 times the volume of your aquarium.
Maintenance:
Ideally a soft, sandy substrate should be employed though it’s not essential. Additional furnishings are as much a case of personal taste as anything else but the most favoured set-ups tend to feature relatively dim lighting plus some chunks of driftwood and scattered roots or branches. One or two flattish, water-worn rocks can also be included to provide potential spawning sites if you wish. Water quality is of the utmost importance since these cichlids are susceptible to deteriorating water quality and should never be introduced to a biologically immature aquarium. The best way to achieve the desired stability is to over-filter the tank using a combination of external canister filters and/or a sump system and perform minimum weekly water changes of 50-70%. If the maintenance regime or diet is insufficient individuals may develop health problems such as head and lateral line erosion or exhibit stunted growth. Mechanical filtration should be tailored to trap small particles stirred up by the fish as sand can cause blockages and wearing issues with filter mechanisms if allowed to continually run through the system.
Water Conditions:
Temperature: 18 – 28°C
pH: 6.0 – 8.0
Hardness: 18 – 268ppm
Diet:
Studies have revealed it to be a generalised omnivore with the natural diet composed of plant material, aquatic invertebrates (particularly chironomid larvae, ostracods and cladocerans), fish scales and fry. Although often referred to as an ‘eartheater’ this species isn’t as benthophagous as members of Geophagus though mouthfuls of substrate are sometimes taken and sifted for edible items. In the aquarium offer good quality, sinking dry foods as staple alongside regular meals of live or frozen bloodworm, Artemia, etc.
Behaviour and Compatibility:
Males are territorial, particularly when spawning, while very small tankmates may be predated upon.
Sexual Dimorphism:
Males grow larger than females, often significantly so, and most dominant specimens develop a nuchal hump to some extent.
Reproduction:
Biparental substrate spawner.
Notes:
This species is also known as the ‘pearlscale’ or ‘mother-of-pearl’ cichlid in deference to the iridescent body scaling.
