The Biology of Avatar 2 Metkayina Clan Explained
James Cameron’s Avatar: The Way of Water introduces us to the Metkayina, an ocean-faring clan inhabiting the distant shores of the Pandoran ocean.
Avatar: The Way of Water introduces us to the Metkayina clan, an oceanic sub-species of the Na’vi. The Metkayina have seemingly adapted to an aquatic lifestyle in the coral reefs of the Pandoran ocean, therefore making them a genetically and morphologically distinct population. Accordingly, there are several physiological differences between the Metkayina clan and the mainland Omaticaya clan.
The first notable difference is the skin and eye color. Unlike the mainland Na’vi, the Metkayina clan have green or turquoise skin with ripple-like stripe patterns along with blue or green eyes. They also have a significantly lighter underbelly and complexion, which may be evidence of countershading- a method of camouflage in which animals have a darker coloration on the upperside (dorsal) of their body and a lighter color on their underside (ventral). It is important to note that this evolutionary adaptation is also present in the newly introduced marine species of Pandora: Tulkun, Akula, and Nalutsa. Countershading is suggested to be an advantageous adaptation in aquatic habitats where light is scattered uniformly throughout the water column.
Moreover, the most notable differences exclusively found in the Metkayina are the forearms and tails. The broad forearms and significantly larger hands may help increase the propelling surface area of the swimmer's hand. Larger propelling surfaces reduce the cost of transport, thus making the design of the Metkayina seemingly optimal for its aquatic habitat. The paddle-like tail seems to act as a powerful horizontal propeller in the water. The mainland Omaticaya however, has a thin prehensile tail that is efficiently adapted for a forest-dwelling lifestyle.
Aside from the differences in the forearm and tail, the chest-to-waist ratio seems to be significantly greater in the Metkayina. It is possible that the development of a wider chest can be related to an increased number of alveoli (tiny air sac structures in the lung that allow for rapid gas exchange). Another physiological difference exclusive to the Metkayina includes the smaller ears and nose. Given their aquatic nature, the narrowing of the nasal passageway and ear canal seems to be an advantageous adaptation to minimize the entry of water into their respiratory system.
Furthermore, an inconspicuous detail that many failed to notice from the film was the presence of a nictitating membrane, an exclusive adaptation to the Metkayina. The nictitating membrane or “third eyelid” seems to act as a layer of protection for swimming. Similar to the human species, the mainland Na’vi has a semilunar fold- a small fold of the membrane in the inner corner of the eye that remains as a vestigial remnant of the nictitating membrane. It is possible that mainland Na’vi populations lost this structure because of changes in habitat and eye physiology, thus rendering the tissue unnecessary.
Overall, the introduction of the Metkayina people has provided many fans with new insights into the biology and evolutionary history of the Na’vi species. Given the multitude of physiological differences found in the Metkayina, it is possible to theorize that they are a separate sub-species that diverged from the mainland lineage. The Metkayina and other oceanic clans can be considered genetically isolated populations that have evolved adaptations favorable to aquatic conditions. Avatar: The Way of Water has introduced a new side of Pandora, which contributes to its vastness and elusive nature.
