In the waters of the Arabian Sea lives a population of humpback whales that does not make the usual seasonal migrations between cold feeding grounds and tropical breeding grounds. These animals remain in warm latitudes all year round, follow a northern breeding cycle, and sing songs unlike any others. A new genetic study strengthens the arguments for recognizing them as a fourth subspecies — Megaptera novaeangliae indica.
Scientists from the Wildlife Conservation Society, together with partners from Oman, analyzed the mitochondrial DNA 2285 of humpback whales from around the world. The results showed a high degree of genetic differentiation of the Arabian population from the three already recognized subspecies — the North Atlantic, North Pacific and Southern. Gene flow between them is minimal, and gene diversity in the Arabian Sea turned out to be the lowest among all the regions studied. The lineages of Arabian whales diverged tens of thousands of years ago — estimates range from 43 to 113 thousand years.
The researchers also studied ancient DNA from the type specimen of Megaptera indica, described back in 1883 off the coast of Iraq. Morphological and genetic analysis confirmed that it was indeed a humpback whale, close to modern Arabian individuals. These data support the proposal to name the subspecies Megaptera novaeangliae indica, although the final decision rests with the Taxonomy Committee of the Society for Marine Mammalogy.
The uniqueness of the population manifests itself not only in its genes. The whales do not migrate, they feed and breed in one area, and they possess a distinctive song culture and behavior. Such isolation makes them especially vulnerable: entanglement in fishing gear, collisions with vessels, underwater noise, pollution and climate change affecting sardine stocks threaten their survival. Their numbers remain small and have not grown for two decades.
Recognition of the subspecies opens the way to more precise conservation measures — from regional management plans to international cooperation through the International Whaling Commission. Without coordinated action, the risk of extinction of this genetically and culturally unique lineage remains high.
