While it may seem counterproductive for members of the same species to eat each other, cannibalism can promote the survival of the species as a whole by reducing competition, culling the weak, and bolstering the strong.
Sand tiger shark eggs develop and hatch inside their mother’s oviducts at different times. When the hatchlings run out of yolk from their own eggs, they eat the other eggs and hatchlings until one baby shark from each oviduct remains. When they emerge, the young sharks are well-nourished, experienced predators who stand a better chance of surviving.
For more cannibalistic creatures, check out the TED-Ed Lesson Cannibalism in the animal kingdom – Bill Schutt
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