Shark Sibling Rivalry

September 28, 2011

Brit Trogen

I consider myself an animal lover, so it's always a little conflicting when I have to come to terms with something like this. Don't get me wrong, I have nothing against sand tiger sharks. Who couldn't love this face?



But any killer that can't control its urges prenatally is a bit much, even by my standards. 


Sand tiger sharks (a threatened species, btw), produce multiple embryos during the first stage of reproduction, but only the strongest of them all survives the trip down the birth canal. Along the way, it also kills and eats it's weaker siblings, feasting on their corpses and yolk sacs to gain strength and take over the womb. Brotherly!


This is the most extreme form of embryonic cannibalism ever recorded; much more brutal than the admittedly creepy reabsorption that can occur between parasitic human twins. Sand tiger embryos develop fully functional teeth and hunting instincts in the womb, leading to full on combat in utero, at which point the mother devotes all resources to the sole surviving offspring.


As with most things, I'm sure you'd prefer to see for yourself. Luckily, someone had the clever idea of snaking a camera into a shark uterus, just for you. Enjoy!




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