Mature fish reach reproductive age in just two weeks

This is the fastest growing vertebrate in the laboratory, even in the natural environment, they grow faster.

A fish that lives in rain pools has defeated its own record - the fastest sex maturity ever known among vertebrates.

According to the researchers' report on Current Biology on August 6, turquoise killi (Nothobranchius furzeri) hatched eggs after unforeseen floods in Mozambique could develop from fry to adult fish. finished ready for reproduction in 14 days. In a pleasant laboratory environment, killi have outgrown other vertebrates, developing in 18 days.

Turquoise killfish.

Study co-author Martin Reichard, an evolutionary ecologist at the Czech Institute of Science in Brno, said that some other vertebrates are nearly as fast-growing as killi, but they go short. For example, house mice sometimes mature in the period of 23-30 days. But they are born at a higher stage of development than fry, Reichard said, and have stimulated growth from breast milk. And a 'mature' goby in 23 days thanks to the development of the gonad on the larvae.

Exploration around the natural wilderness of killi knows that this fish possesses a much more impressive feat. The fry can grow from just 5mm up to 54mm with the gonads active in just two weeks. When rainwater pools dry up, fertilized eggs can survive without incubation for months until the rain returns.

According to Reichard, this fish 'doesn't waste time on anything'. 'Mating does not require too much time to learn.' The male simply stretches his fin, and if it is accepted, the female will lay an egg before swimming to find another partner. A female lays between 20 and 100 eggs a day, 'usually before noon'.