"Red Prince"

Adults reach a length of 5–6 cm; it is worth noting that females are usually slightly larger than males. Males, on the other hand, are distinguished by more intense coloration, especially in selective forms, displaying bright golden-red tones. They also have a modified anal fin, known as an andropodium, which is used to transfer sperm during mating.

The species is known from a very small area in north-central Mexico, in the state of Durango. The first wild specimens were discovered in the basin of the small Mezquital River (Río San Pedro Mezquital) near the El Saltito waterfall in central Mexico. This area is characterized by an arid climate, dominated by steppe or semi-desert vegetation. The fish prefers shallow water areas, especially those where the water is stagnant and slightly murky, with abundant aquatic flora. The substrate usually consists of dense mud mixed with stones and rock formations. Currently, the existence of this species is under threat. Human activities, such as water pollution and general habitat alteration, have unfortunately led to a critical reduction in their population.

These fish are quite calm towards other species and get along well with similarly sized tankmates that can live in similar conditions. Within their own species, relationships are based on male dominance in a certain area. Providing sufficient space and dense vegetation helps reduce aggression and prevent potential conflicts. They can be kept in a group.

For a small group of these fish, a shallow aquarium of 100 L or more is quite sufficient. When decorating, it is advisable to use fine-grained substrate and provide an abundance of rooted and floating plants to create dense thickets. Additional decorative elements can be installed at the aquarist's discretion. The filtration system and other equipment should be placed and configured to create minimal current. Although the "Red Prince" does not have strict requirements for water composition, its high quality is critically important. Therefore, weekly water changes of 15–20% of the volume are a mandatory procedure.

In their natural habitat, the fish's diet consists of small invertebrates and diatoms. For fish kept in a home aquarium, the main part of the diet should be live or frozen meaty foods, such as bloodworms, daphnia, and artemia, supplemented with vegetable additives. As an alternative, high-quality dry foods with a high protein content are suitable; they play a secondary role, serving to diversify the diet.

The "Red Prince" is a live-bearing species, which means that females do not lay eggs but give birth to fully formed offspring, as the entire incubation period takes place inside the female's body. The breeding season usually lasts from March to September. The incubation period is 50–55 days, after which about a dozen fairly large fry emerge, which are already capable of feeding on artemia nauplii. Parental instincts in these fish are poorly developed, and adults may eat their offspring. For this reason, it is recommended to transfer the fry to a separate tank.

Health problems in these fish arise only in the presence of injuries or keeping in unsuitable conditions, which leads to a weakening of the immune system and the subsequent occurrence of various diseases. At the first signs of illness, it is necessary first to check the water parameters for exceeding permissible values or the presence of toxic substances (such as nitrites, nitrates, ammonia). If deviations are found, all indicators should be normalized, and then treatment should begin.

When purchasing, choose active fish with clean fins and no visible damage to the body. Avoid individuals with signs of emaciation, sunken bellies, or unnatural behavior, such as constantly hovering near the surface or trying to hide from tankmates in the corner of the aquarium. It is advisable to acquire fish from a single source to minimize the risk of introducing infections, and to clarify their keeping conditions at the store for smooth adaptation to the new aquarium.