Néon

In 1894, John William Strutt Rayleigh and William Ramsay discover argon, the first noble gas. In 1895, Ramsay also isolates helium, previously known only in the solar spectrum, from uranium ores. According to the laws of the periodic table, he recognizes that there must be another element between helium and argon with an atomic mass of about 20 u. From 1896, he therefore begins to study various minerals and meteorites as well as the gases they emit when heated or dissolved. However, Ramsay and his colleague Morris William Travers fail to achieve conclusive results, and manage to find only helium and, more rarely, argon. They then investigate the hot gases from Cauterets in France and Iceland, without result. Finally, they begin to examine 15 liters of crude argon isolated from liquid air and separated by liquefaction and fractional distillation. The first element to be separated and detected by flame spectrum is krypton. On June 13, 1898, they finally succeed in isolating a lighter element from the fraction with the lowest boiling point of crude argon. Ramsay and Travers decide to name this element Neon, from the Greek νέος / neos, 'new'. Shortly thereafter, they successfully extract another element, xenon, using the same process. The first application of the newly discovered gas is the neon lamp developed in 1910 by Frenchman Georges Claude: neon filling a glass tube is excited by high voltages and emits light.

In nature, this fish lives in schools of hundreds of individuals. It uses its bright colors to keep track of its school in turbid, dark or amber-colored waters. Peaceful, this fish remains a characin, so a hierarchy will be established in the group. Quite lively, it can very well pursue fry or seem to have 'a little burst of madness'. Unfortunately, this small fish is cardiac-prone. A lack of hiding places, sudden gestures in front of the aquarium, tankmates that are too dynamic, teasing or aggressive can, more or less in the long term, weaken the neons or even reduce their life expectancy.

At adulthood, the neon tetra measures about 3-5 cm. The male is slimmer than the female, and its blue line would be more straight; but both sexes are the same size.

This fish originates from South America, more precisely from southern Peru, Colombia and Brazil. The pH of the water in its natural environment varies between 6 and 7. The water is poorly mineralized and comes directly from the Andes Mountains at a fairly cool temperature of 18 to 25°C, characteristic of melted mountain water. The water in which it lives is therefore soft (GH less than 10) and slightly acidic (pH between 6 and 7 at most). In captivity, it is better to follow these parameters, otherwise it will be weakened and see its lifespan reduced to only 2 years or sometimes much less. Under good maintenance conditions, they can live up to 8-10 years.

It is an omnivorous species with a carnivorous tendency, and more precisely insectivorous. It likes mosquito larvae, tubifex worms, artemia and daphnias. Vary its diet for better health and beautiful colors.