Alert Diver Category: Parting Shot

The common seadragon (Phyllopteryx taeniolatus) is anything but. Found only in Australia’s temperate coastal waters, this spectacular seahorse relative — also called the weedy seadragon — grows up to 18 inches long and is painted beautiful colors and whimsically festooned with teardrop-shaped skin flaps.

Like many octopuses, the female greater blue-ringed octopus (Hapalochlaena lunulata) is a semelparous animal, which means she reproduces once and then dies. After she lays a clutch of eggs, she quits eating and wastes away while protecting her eggs, dying shortly after her eggs hatch.