We occasionally have very attractive offspring of the “Northern Mountain Swordtail” in stock. When we receive them, the fish are usually young adults, i.e., the sword of the males is still relatively short or not yet visible. For comparison, we also show a fully grown male here.
X. nezahualcoyotl used to be considered a local variant of X. montezumae. The species name refers to Nezahualcoyotl (1402-1472), the poet-philosopher-emperor of Tezcoco (Texcoco). He ruled as an equal partner of Montezuma, the ruler of the Aztecs in the Aztec Triple Alliance. The name was chosen because the species is considered a sister taxon of X. montezumae.
X. nezahualcoyotl is only found in the headwaters of some rivers in the state of San Lous Potosi in Mexico. The water there is clear, the ground rocky, and the temperatures moderate (22-24°C). Caring for this small swordtail – the body length rarely exceeds 4 cm (the largest wild-caught male measured had a standard length of 48 mm), plus the fins – is not very difficult, but good water hygiene must be ensured. It is important that the pH should not fall below 7 on a permanent basis, preferably around 8, and to ensure this the water should be at least medium hard. They will eat any commercially available ornamental fish food of a suitable size.
Incidentally, this species can occur with or without black speckles. The black speckles shown in the pictures are linked to the Y chromosome and are therefore inherited from the father. If you want to breed X. nezahualcoyotl without black speckles, you must therefore choose an unspeckled male as a breeding animal. The litter intervals for X. nezahualcoyotl are 4-6 weeks, with usually between 10 and 40 young animals per litter.
For our customers: the animals have code 476562 on our stock list. Please note that we only supply wholesale.
Text & photos: Frank Schäfer
