The redtail splitfin (Xenotoca eiseni) – a livebearer with character
The redtail splitfin (Xenotoca eiseni) is a real gem for many aquarists. So if you want to add a touch of vivid elegance to your aquarium, the redtail splitfin will be your perfect choice. With dazzling colors, interesting reproduction habits and peaceful nature, this magnificent livebearer will win the hearts of beginners and experienced aquarists alike. Get to know the redtail splitfins better and see why they are so interesting.
Where do redtail splitfins live?
Redtail splitfin is an endemic species that inhabits waters in the Mexican states of Nayarit and Jelisco. It has been observed in the upper part of the catchment areas of the Coahuyana, Armeria, Huicicila and Ameka rivers, in the Magdalena and Etzatlan drainless basins, as well as in the springs and small streams of the northwestern Santiago River basin, near the city of Tepic. It is worth noting, however, that after the three redtail splitfin species, namely X. doadrioi, X. lyonsi, X. eiseni, had been isolated and described by Domínguez-Domínguez et al., it turned out that the range of the species in question is limited only to the upper reaches of the Huicicila River and the lower Santiago River basin. This situation may change with further research.
Redtail splitfins inhabit a wide variety of habitats, such as rivers, streams and ponds with both clear and turbid water. The bottom of their habitats can be covered with silt, sand, as well as stones. These are both habitats with standing water and fairly strong currents.
It should be noted that due to human activities, including habitat degradation and the introduction of non-native species, natural populations of redtail splitfin (Xenotoca eiseni) have faced many threats. Their population is highly fragmented. In some areas, the species is completely extinct. For this reason, the redtail splitfin has been included on the IUCN Red List of endangered species. Fortunately, there are number of programs aimed at protecting and preserving these beautiful fish in their native habitats. Remember that when you buy captive-bred fish, you support the conservation of the species!
Characteristics of redtail splitfin (Xenotoca eiseni)
One of the most captivating features of redtail splitfins is their mesmerizing appearance. With vivid colors and intriguing patterns, these fish are quite an attraction in any aquarium. Males are known for their stunning combination of bold shades of red, orange and blue. Females, though less extravagant, are captivating with their elegant silver coloration. They have a clearly rounded abdominal area and a visible pregnancy spot. Females grow to about 7 cm in length, while males are only slightly smaller, reaching a length of about 6 cm.
The redtail splitfin belongs to the viviparous family (Goodeidae). Males have an andropodium, a copulatory organ formed from the transformation of the first rays of the anal fin. With the help of the andropodium, the male places sperm in the female’s reproductive tract, where the egg is fertilized. After a gestation period of 4 to 6 weeks, the female gives birth to fairly large young (1-2 cm) fish, which are ready to explore the aquatic world on their own. Witnessing the birth of redtail splitfin fry is an amazing experience for any aquarium lover.
Aquarium for redtail splitfins
Redtail splitfins are large and energetic fish. Their aquarium should have a minimum capacity of 100 liters (for 5-10 fish). You need to ensure an adequate swimming space and ample hiding places arranged by planting plants and placing roots and stones in the tank. It is best to keep a group of fish with a predominance of females. Males may engage in harmless fights with each other, as well as harass females with courtship. However, if you keep slightly more females than males, this should not be a problem. Sometimes aggressive behavior of redtail splitfins towards other fish species is observed in general aquariums, especially when they are kept alone or in pairs. Especially avoid keeping redtail splitfins together with long-finned fish, as the former will bite the latter.
It is essential to provide good filtration in the aquarium, which is crucial for maintaining optimal water quality.
Water parameters for redtail splitfins
Redtail splitfins feel best in water temperatures between 22°C and 26°C. However, it is worth knowing that they can cope well with seasonal changes in water temperature. They are healthier, stronger and live longer if they are provided with lower temperatures during winter. Usually about 15°C is recommended for two to three months, but for short periods they can endure even at 10°C. For this reason, they are sometimes kept outdoors in ponds during the warmer months, and moved indoors during winter.
The ideal water pH range for redtail splitfins is 7.0-8.0 pH. They can tolerate slightly acidic or alkaline water, but the key is to avoid extreme fluctuations in pH values to prevent stress and health problems. As for water hardness, this species prefers medium-hard to hard water. It is best to keep total hardness (GH) at 10-15 dGH, and carbonate hardness (KH) at 8-12 dKH. This range will reflect conditions in their natural environment and help keep them in good shape.
Like all other aquarium fish, redtail splitfins are sensitive to the presence of ammonia and nitrite in the water, which are harmful to their health. It is therefore extremely important to keep the concentration of these compounds at zero levels by ensuring that the aquarium has efficient nitrification. On the other hand, the concentration of nitrates should not exceed 20-40 ppm, hence the importance of regular water changes. Redtail splitfins tolerate a slightly brackish environment. However, it is important to acclimate the fish slowly if you decide to add a small amount of marine salt to the water.
What to feed redtail splitfins?
It is an omnivorous species that readily accepts multi-ingredient flake and granulated foods and frozen invertebrates. In the wild, redtail splitfins also eat algae and aquatic plants; so consider including them in their diet in the form of the following foods with algae: Spirulina Flakes, 3-Algae Flakes, Super Spirulina Forte. Recommended multi-ingredient foods for redtail splitfins include: Supervit Flakes, Red Mico Colour Sticks, Vitality & Color Granules. To boost their immunity, you can feed them with Tropical D-Allio Plus and foods from the Pro Defence line.
Redtail splitfins are not skittish and can even be kept with aquatic turtles, as they are fast enough to escape attacks from predators.
Literature
Domínguez-Domínguez O. at all (2016), Two new species of the genus Xenotoca Hubbs and Turner, 1939 (Teleostei, Goodeidae) from central-western Mexico, Zootaxa 4189 (1): 081–098
