Fish embryos decide when they want to be born, Israeli researchers find
Groundbreaking study of largest group of living vertebrates finds that embryos release a neurohormone that makes them initiate hatching, offering insight into survival strategies
Reporter at The Times of Israel
Hebrew University researchers say they have discovered that fish embryos are able to decide when they want to be born.
Dr. Matan Golan from the university’s Volcani Institute, who led the team of researchers — including Yuni Nahmias, Itay Oz, Genevieve Fernandes, Matan Golan and Deodatta Gajbhiye — found that fish embryos choose their optimal birthday, and then initiate hatching through a signal from their brain.
The findings reveal the long-sought neuronal mechanism which controls hatching in fish.
The neurohormone Thyrotropin-Releasing Hormone (TRH) travels via the bloodstream to a specialized gland. This triggers the release of enzymes that dissolve the egg wall, allowing the embryo to break free.
The scientists said that without TRH, embryos are unable to release the enzymes, resulting in their death inside the egg.
Hatching is a critical moment for any egg-laying species.
If an embryo hatches too soon, it might not be ready for life outside the egg. If it waits too long, it could miss its chance to survive.
Since fish are the largest group of living vertebrates, the researchers said the findings could offer new insights into neurobiology, survival strategies and environmental adaptation in vertebrates.
The researchers plan to explore how TRH and other neuroendocrine factors influence hatching in other species.
The findings by the Israeli researchers recently appeared in the peer-reviewed journal Science.
