The Redtail Splitfin, scientifically known as Xenotoca doadrioi, is a captivating and relatively rare species of freshwater fish native to the rivers and streams of Mexico. This species is particularly noted for its striking coloration and active behavior, making it a favorite among aquarists who appreciate unique and visually appealing fish.

Redtail Splitfins are characterized by their robust, laterally compressed bodies and vibrant colors. The males are especially striking, with a vivid red or orange tail and a bright blue body adorned with iridescent scales. Females are generally less colorful, exhibiting a more subdued gray or silver hue. Both sexes have a distinct, deep caudal peduncle and a split or forked tail, which is where their common name, "Splitfin," originates.

In captivity, Redtail Splitfins thrive in a well-maintained aquarium that replicates their natural habitat. They prefer a tank with plenty of open swimming space, as well as areas with dense vegetation or decorations such as rocks and driftwood to provide hiding spots and resting areas. A dark substrate can help enhance their colors, making them even more striking.

Water conditions should be slightly alkaline to neutral, with moderate hardness. Maintaining stable water parameters through regular water changes and efficient filtration is crucial for the health and well-being of Redtail Splitfins. They are relatively hardy fish but do best in stable environments with clean water.

Redtail Splitfins are social, live-bearing fish and should be kept in groups to promote their well-being and natural behavior. A ratio of more females to males is recommended to reduce stress and aggression among males. They are generally peaceful and can be housed with other similarly sized, non-aggressive fish, making them ideal for community tanks.

Their diet should be varied to ensure they receive all the necessary nutrients. Redtail Splitfins are omnivorous and will readily accept high-quality flake foods, small pellets, and live or frozen foods such as brine shrimp, daphnia, and bloodworms. Including some vegetable matter, like spirulina flakes or blanched spinach, can also be beneficial.

Breeding Redtail Splitfins in captivity is relatively straightforward. As livebearers, they give birth to free-swimming fry rather than laying eggs. To encourage breeding, maintain optimal water conditions and provide plenty of cover for the fry, such as dense plants or breeding mops. The fry can be fed with finely crushed flake food or specialized fry food until they are large enough to accept standard fare.

Overall, the Redtail Splitfin is an excellent choice for aquarists looking for a colorful, active, and relatively easy-to-care-for species. Their striking appearance, peaceful nature, and ease of care make them a delightful addition to any well-maintained community aquarium. With proper care, they can thrive and bring a burst of vibrant color and dynamic activity to your aquatic setup.