Green Neon Rasbora

About

Sometimes sold as the green neon rasbora or kubotai rasbora, Microdevario kubotai is a genuinely miniature fish, adults rarely exceed three-quarters of an inch, belonging to a genus defined by what biologists call miniaturisation, where the fish reach sexual maturity at a remarkably reduced body size. It hails from Thailand, where it inhabits slow-moving, often nutrient-poor forest waters, and that natural setting gives you a good template for the aquarium: soft, slightly acidic water and dense planting will bring out its best colours. This is a schooling species that moves in large groups in the wild, so keeping at least eight to ten individuals is genuinely important rather than just a suggestion. A proper group will be noticeably bolder and less skittish, and males competing for female attention will show their most vivid colouration. Because of its tiny size, tankmate selection matters. Other small Thai species like Boraras or Trigonostigma make natural companions, while anything significantly larger risks intimidating or eating them. Breeding is achievable with some effort; the fish scatter eggs among fine-leaved plants and ignore them afterward, so separating adults after spawning is necessary if you want to raise fry. A rewarding species, but one that benefits from a keeper who pays attention to the details.