In the Atlantic waters, a rare tailless dwarf orca was spotted.

In November 2024, marine biologists from Germany were traversing the waters of the Atlantic aboard a research vessel when they spotted a pod of three dwarf orcas, a rare sight in the central region of the ocean. One individual swam differently from the others; instead of moving its tail (or what remained of it) up and down, it swung it from side to side. The orca was missing its tail fin. It appeared that the animal had adapted, had not forgotten how to swim, and kept pace with its companions.

2025-02-21 10:00:47https://naked-science.ru/article/biology/dwarf-orca-without-tail

Wild animals often become disabled for various reasons. Primates have been found born without one of their limbs or with a deformed jaw. Animals are affected by diseases such as frambesia (a bacterial skin infection) and other zoonoses—pathogens transmitted from humans. Additionally, car accidents, traps set by hunters and poachers, and other causes of injury sometimes result in animals losing part of a limb, if not their lives.

A meta-analysis conducted in 2023 showed that in 60% of scientific studies on animals with disabilities (68 out of 114 examined articles), injuries were presumably or proven to be the result of human activity. Another conclusion from the same meta-analysis is that animals can adapt quite successfully to living in challenging circumstances. The study primarily focused on primates, with authors citing examples of chimpanzees, gorillas, and macaques that learned to walk and climb trees in their unique way, as well as how howler monkeys could use their tails to compensate for a missing limb, and so forth.

In a new report published in the journal Marine Biodiversity, marine biologists reported the discovery of a dwarf orca (Feresa attenuata) without a tail. This rare species, measuring slightly more than two meters in length (about the size of an average human), can be found in subtropical seas and oceans. Researchers managed to encounter it in the central Atlantic, 540 kilometers from the Cape Verde Islands (located near West Africa) on November 1, 2024.

Experts were surprised that, despite the injury—where the absence of a tail in members of the dolphin family is comparable to the absence of legs or feet in land mammals—the dwarf orca swam alongside two companions. The injured orca separated from the group, remaining near the stationary research vessel RV METEOR (where it was photographed) for about 15 minutes before rejoining the others.

Visually, specialists noted that the stump of the tail on this orca had healed well, although while her companions jumped out of the water and surfed, she stayed nearby and did not participate. It remains unclear how the animal lost part of its tail fin. Researchers suggest that the orca likely got tangled in fishing gear. Biologists did not observe any significant marks that might indicate a shark attack.

As scientists pointed out, the orca has learned to control its injured tail in a new way: instead of moving it up and down, it moves sideways, turning its entire body. A similar swimming method has been observed in dolphins and whales that also lost their tail fins—suggesting this may be a common adaptation strategy.

“Our observations of this individual—its healing wound, clear ability to feed, and connection with a small group—likely indicate that the animal can cope with its deficiency. This underscores the need to preserve nature and practice responsible fishing,” the authors of the article emphasized, adding that their report will help identify this orca in the future.