Jellyfish have radial symmetry, meaning that if you sliced a jellyfish down the middle, the parts would be symmetrical, like the segments of an orange. These cnidarians are famous for their stinging ...

Jellyfish like the dreaded Portuguese man-of-war are also related to corals, but they’re part of a different subgroup, the siphonophores, which practice an unusual form of collective living.

What most of us would recognise as a jellyfish - the otherworldly, gelatinous aquatic animals renowned for their sting-filled tentacles - is actually just the final stage of these animals' life cycle.

Jellyfish are known for drifting to and fro at the whim of ocean currents—but not all species are so passive. The millions of golden jellyfish that pack Palau’s Jellyfish Lake spend much of ...

Part of what makes this jellyfish so unique­—and somewhat terrifying at the same time—are the four ribbon-like arms that extend from its mouth. The arms can grow upwards of 33 feet in length ...