They Grow Up so Quickly...

It’s no secret that a tough environment can force you to grow up fast and any parent will tell you that kids today seem to leave their childhoods behind all too quickly. So spare a thought for a tiny species of Killifish whose young go from hatching to full sexual maturity in a record-breaking seventeen days – the shortest period for any vertebrate on earth. 

Nothobranchius kadleci is an amazing yet tiny fish that makes its home in an extreme environment and is therefore forced to take equally extreme measures in order to survive. In the wild, these fish live in temporary pools in southern Mozambique that only occur during the rainy season when savannah depressions are filled with water. Given such intense conditions, it’s, therefore, a great advantage for them to mature very quickly, as their habitat may dry out in three to four weeks. During the drought, this species remains in the soil as dormant eggs and embryos, and when the rains return (which could be more than a year) these hatch and then repeat the lifecycle once again.

And as if that were not impressive enough, Scientists found that one of the groups of fish under study grew nearly a quarter of their total body length per day, while some of N. kadleci’s eggs reached the hatching stage in fifteen days, meaning they also hold the record for the shortest minimum generation time in vertebrates.