Eels and sharks have different methods of reproduction. Sharks are ovoviviparous, which means that their eggs hatch inside the mother's body and the embryos are nourished by a placental sac. Eels are oviparous, meaning that they lay eggs outside of their body. The eggs of eels are sticky, so they attach to surfaces like rocks and logs. After hatching, the larvae live in the water column until they are big enough to fend for themselves.