The zebrafish is about 2.5 cm to 4 cm long. In its larval stages it is transparent and as it matures to an adult it develops stripes that run along the length of the body and look blue in colour. Glowing neon-coloured fish, trademarked Glofish, became the world's first genetically engineered species to be commercially available in the 2000s, and their 'production' simply skyrocketed thereafter.
These Glofish are essentially zebrafish (Danio rerio), but with fluorescent jellyfish genes endowed in them.
