The greatest migration on Earth happens twice each night in the ocean. Every evening at sunet, zooplankton, followed by predator fish, squid, octopus and other species that have acquired a taste for plankton, start moving up from the deep waters of the ocean. In this vertical migration to the surface, the zooplankton feast on plant plankton and other tasty morsels in the water as well as on each other. The feeding ends just before dawn when the plankton retreat to the depths of the ocean to hide during the day until, once again, the next evening, they migrate back up the water column.
In Planktonia, Erich Hoyt invites readers to dive into the secret world of the nighttime ocean. Countless microsopic plankton – creatures such as the ornate ghost pipefish, left-handed hermit crabs and bony-eared assfish – are delicate and beautiful; some look terrifying. This massive vertical migration attracts larger creatures, too, such as the solitary 6-inch (15 cm) bigfin reef squid and the fierce and hungry 6 1/2-foot (2 m) female blanket octopus. Everyone joins the migration for the midnight feast, and they are all ravenously hungry.