Geophagus pellegrini
Geophagus pellegrini or Geophagus yellowjacket naturally inhabits the San Juan River basin in northwestern Colombia, South America. The fish can be found both in the main channel of the river and in narrow channels that are no more than 3 metres wide and up to 1 metre deep. The water in these areas is clear and the substrate is a mixture of gravel, sand, mud and clay.
The fish gets its name after Jacques Pellegrini, the French zoologist who first described it. Although these fish are not difficult to keep or breed, they are nevertheless quite rare in aquarists' collections.
Geophagus pellegrini has a yellowish or orange body coloration with transverse broad dark stripes. Adult males are larger than females and have elongated fins. In addition, they eventually develop a hump at the back of the head. The maximum size of fish is 13-15.5 cm.
Geophagus pellegrini fish are generally peaceful and do not disturb other fish species, even smaller, living with them in the same aquarium. They only show signs of aggression during the spawning season, when they are protecting their nest and offspring. Keep geofagus Pelligrini preferably in a group of 5-8 individuals, among which, over time, stand out the dominant male. For such a number of fish need an aquarium of about 300 liters.
The most important decoration element is the soft sandy substrate, which plays an important role in the nutrition of the fish. Coarser substrate such as gravel or small pebbles may damage the gill filaments or even get stuck in them, as the fish feed by sifting through their gills.
Several large snags and flat stones can be placed on the bottom to serve as potential spawning spots.
By water quality higher demands, as fish are very sensitive to changes in its chemical parameters, and therefore launch them into the aquarium, which has not yet established biological balance is categorically impossible.
Water parameters: temperature 25-30° C, hardness dH 0-5°, pH 5,0-6,0. Requires filtration, aeration and weekly replacement of at least ½ of the aquarium water with fresh.
In nature Geophagus pellegrini feeds on small aquatic and terrestrial insects, plant seeds, organic detritus and sediments. In an aquarium, the fish are fed with artemia, daphnia and chironomid. The fish also like pelleted and flaked food containing spirulina. The food should preferably be fed 3-4 times a day in small portions.
Reproduction
The Geophagus pellegrini breed under suitable keeping conditions.
During the spawning season, the alpha male forms a temporary pair with one of the females. It is not uncommon for this pair to remain for quite a long time. The pair selects a spawning spot, which is usually a flat surface of a large rock.
The female hatches 20-40 eggs and after fertilization by the male collects them all in her mouth, where the eggs are incubated for a few days. The hatched larvae stay in the female's mouth for the first 2-3 days of life. Occasionally she releases the fry to feed. Gradually, as the fry become more robust, their free swimming time increases. The male takes part in the care of the offspring by protecting the female and the fry from other fish.
The fry are fed with Artemia at least 4 times a day.