Fish embryos can control hatching timing, study finds

A study from Hebrew University of Jerusalem reveals that fish embryos can control their hatching timing, effectively choosing their own birthdays. Researchers found that the hormone thyrotropin-releasing hormone (Trh) plays a key role in this process. The study focused on zebrafish and medaka, showing that both species use a similar Trh-triggered mechanism to time their hatching. This process is influenced by environmental factors, with zebrafish typically hatching at daylight. Future research will explore hatching processes in other fish species and how climate change may affect these evolved behaviors. The findings were published in the journal Science.