Retroculus xinguensis
Retroculus xinguensis naturally inhabits the Shingu River of the same name flowing in Brazil, South America. There is also information that these fish have also been found in the Tapajos River basin. The fish stay in very fast currents, with sandy and rocky substrate and large boulders on the bottom. They are not the most popular cichlids among aquarists, due to their unsightliness, as well as the requirements of a strong water current in the aquarium, unsuitable for the bulk of freshwater fish.
Adult males Retroculus xinguensis significantly slimmer than females, and this is clearly visible in the area between the pelvic and anal fins, which males are almost straight and females rounded. The basic coloration is yellow-green-grayish. The body can be seen broad dark transverse stripes. In males, pelvic fins with a red tint. During the breeding period, the coloration of males becomes more contrasting, the head on each side turns red and the dorsal anal and pelvic fins are red. Determining the sex of young fish is impossible. The maximum size of males is about 20 cm and females about 15 cm.
Retroculus xinguensis are generally peaceful fish, but not during the spawning period when they become territorial and violently attack other fish that swim into their territory. Keep Retroculus xinguensis recommended flock of 5-8 fish. Over time, the group will form a dominance hierarchy in which the smaller and weaker fish will obey the larger and stronger. When kept in smaller numbers weaker individuals will be a constant object of harassment.
Retroculus xinguensis keep desirable in a species aquarium of 700 liters, which should recreate a strong current of water, resembling a flowing river, using a water pump. The substrate used is a mixture of river sand with fine polished gravel. At the bottom are placed large stones and snags. It is possible to plant and live plants, but you should choose their types, which can grow attached to the objects of decoration.
Water parameters: temperature 26 - 32° C, hardness dH 1-12°, pH 6,0-8,0. Requires strong filtration and aeration, as well as a weekly substitution of 1/2 of the aquarium water with fresh. The water in the aquarium should be crystal clear and free of excessive concentrations of organics.
In nature, the fish's menu consists of small invertebrates: midges, caddisflies and mayflies. In an aquarium, the fish are fed artemia, Tubifex, chopped earthworms. Also give the fish flake food containing spirulina. Feed the fish preferably in small portions three times a day.
Reproduction
For successful breeding Retroculus xinguensis, two requirements must be met: varied feeding and a weekly change of at least ½ of the aquarium water with fresh water.
If there are no mature adults, it is best to start with a group of young fish and allow the pairs to form naturally. A certain degree of patience is required when breeding fish, as it may take at least a year or possibly two until they are sexually mature.
Spawning is preceded by male courtship. Producers dig several small holes in the substrate together. In one of these holes the female lays eggs. Spawning is batch. The male immediately fertilizes the eggs. During the spawning period, the female hatches about 200 eggs. The eggs are very sticky and quickly become covered in sand. After spawning, the producers bury the hole with the eggs with a layer of sand.
After 3-4 days, the larvae hatch out of the eggs and remain in the nest until their yolk sacs have completely dissolved. As soon as the fry begin to swim they begin to be fed artemia at least 4 times a day. Parents take care of fry 2-3 weeks, sending them to the nest at dusk.
Retroculus xinguensis lifespan is about 10 years.
