Requiem sharkCarcharhinidae

A requiem shark is born attached to its mother.

Most sharks finish their investment early. The egg is packed with yolk, and whether it is laid in a case or carried inside the body until it hatches, the embryo lives on that yolk and nothing else. This family runs a pregnancy instead. When the yolk sac empties, its stalk fuses into the wall of the uterus and becomes a placenta, and the mother feeds the pup from her own bloodstream for the rest of the term. It is the solution mammals arrived at, reached separately, and almost nothing outside mammals does it. Pups come out fully formed and swimming, with a fresh umbilical scar on the belly that stays visible for weeks and lets a researcher put an age in days on a newborn shark. The tiger shark is the exception in this family and keeps its young on yolk to the end.

That kind of pregnancy takes most of a year or longer, produces a handful of large pups instead of a cloud of eggs, and is followed by years before those pups breed anything themselves. In a sea nobody is fishing it works beautifully. It is also why this family falls apart fastest under pressure: the oceanic whitetip, once among the most abundant large predators in the open ocean, is now listed as critically endangered.

These are the sharks you actually meet. Thirteen of them are on the 🌊 Red Sea list and between them they cover every situation on this coast: blacktip reef sharks working a lagoon in water too shallow to cover them, reef sharks patrolling a wall in formation, silky and oceanic whitetip sharks hanging in the blue off the offshore reefs, and the tiger shark, which eats whatever there is. One body plan at every size, refined and then left alone. The shape anybody draws when told to draw a shark is this family's shape.