Kids can marvel at the fastest-growing fish in the world, growing from egg to adult in just six weeks. The adult can reach up to 2" (7 cm) in length. The Killifish eggs used in the kit are from the same family of Killifish eggs that were flown and studied by NASA on the space station. These eggs are homegrown in the USA and raised in Toyops labs to preserve their native habitats. Owners just add bottled water and a light source to watch them spring to life. Launch date: March 2010.