11. Daphnia ) exhibit diel vertical migration . 12. This movement pattern is known as Diel vertical migration and is also exhibited by other oceanic organisms. 13. This vertical migration behavior is believed to be a chemical reaction, rather than a visual or mechanical. 14. These vertical migrations often occur over large vertical distances, and are undertaken with the assistance of a swimbladder. 15. This is a major process in the ocean and without vertical migration it wouldn t be nearly as efficient. 16. They descend to the mesopelagic zone as they mature, but do not exhibit a diel vertical migration pattern. 17. These movements are thought to be in response to the vertical migrations of prey organisms in the deep scattering layer. 18. These vertical migrations often occur over large vertical distances, and are undertaken with the assistance of a swim bladder. 19. They usually live at altitudes of and up to nearly during the warm seasons but may make seasonal vertical migration . 20. Based on catch records, the cookiecutter shark appears to conduct a diel vertical migration of up to each way.
