Location
The redhump eartheater is native to river drainages and lakes in South America, particularly Colombia and Venezuela. It lives in water that is slightly acidic to neutral (6.5 to 7.0 pH) and about 24 to 26 degrees Celsius (75-79 F). It is stenohaline, found only in mainland freshwater environments, and is endemic to neotropical environments in South America.
Food Items
Wild redhump eartheaters take substrate material into their mouths and sift out inedible bits of sand or gravel, while consuming detritus and small organisms. In captivity, the redhump eartheater readily accepts most types of prepared fish foods, as well as finely chopped vegetables, shelled peas, frozen bloodworms (mosquito larvae), and blackworms.
Captive Care
The redhump eartheater is commonly available in the aquarium trade, and relatively easy to maintain. Adults should be kept in aquariums of at least 200 liters (50 gallons); juveniles in no less than 110 liters (30 gallons). This fish has a habit of taking substrate into its mouth and spitting it back out or sifting it through its gills. It is likely to uproot aquarium plants if they are not secured or well established.
Redhump eartheater tends to be aggressive toward conspecifics, especially large males. Adult males of this species will not tolerate other males or females carrying a brood. Females can be kept in groups, but will become aggressive in smaller aquariums. Redhump eartheaters tend to resemble African cichlids, especially the mbuna of Lake Malawi, in their behavior, level of aggression, and breeding patterns.
Reproduction
Redhump eartheaters are immediate maternal mouthbrooders. These fish grow relatively quickly, and can be sexed as subadults. Sexual dimorphism is clear - males have a large, red nuptial hump on their heads and grow larger than the females. Mature males will develop an iridescence on the scales on their sides and very large humps. The redhump eartheater is easy to breed and will condition rapidly on a diet of frozen and live foods. Males will display to females by opening their mouths and flaring their gills. Non-receptive females may be driven from the spawning area. Spawning takes place on a smooth rock or clean sand bed. The female will lay one or two eggs, then the male will fertilize them. The female will immediately take the fertilized eggs into her mouth and proceed to lay more eggs. This will continue until spawning is completed. The female will carry the eggs until they are free-swimming and have absorbed their yolk sacs, approximately 2–3 weeks. She will accept little to no food during this period. Eventually, she will release them and allow them to search for food, taking them back into her mouth when she feels threatened. The brooding female will often signal to her fry when danger is present, and will shut her fry out of her mouth when encouraging then to forage. At this point, the breeder may choose to strip the young from the female's mouth and separate them so that she will eat again. Some breeders choose to strip the female after fertilization and incubate the eggs artificially.
