“Shy” and “docile,” That’s how Nate Jaros of The Aquarium of the Pacific describes sand tiger sharks. The story is different, though, when these species are in the womb.
Sand tiger shark “eggs hatch in the uterine chamber when the embryos are about 17 cm (6.7 in) in length. The largest and most advanced embryo in each chamber (usually the first hatched) kills and consumes younger developing siblings (intrauterine cannibalism). After preying on their siblings, the two remaining embryos feed on any eggs present.