Scientists very rarely get access to most sharks, the development of their young or the nursery grounds where they grow. So seeing a hammerhead shark(Sphyrna tiburo) embryo, halfway through its five-month development, is very unusual.
Access to growing embryos is key for developmental biologists like me as we try to understand the diversity of animals on Earth. Usually the fishes I study, including other shark species, lay eggs, which allows us to easily watch development in real time.
