Photograph by Tim Laman, National Geographic
Ribbons of red nudibranch eggs curl near Malaysia's Mabul Island. Nudibranchs, also called sea slugs, lay their eggs on the seafloor, attached to coral or rocks. Although a nudibranch is a simultaneous hermaphrodite (possessing both male and female reproductive organs), it reproduces by finding a partner. Millions of eggs can be found in one egg spiral.