The only living species in the genus Orcinus is the orca, formally named Orcinus orca.
The orca is also called the killer whale, although it is biologically the largest member of the dolphin family, Delphinidae. Its scientific classification places it among toothed whales and oceanic dolphins rather than in the family of true whales. The genus name Orcinus refers to the underworld in Latin tradition and is associated with the animal’s formidable reputation as a predator.
Orcas are found in oceans worldwide and are recognizable by their black-and-white pattern, tall dorsal fin, and powerful bodies. Different populations may specialize in fish, rays, sharks, seals, dolphins, or other prey. These populations can develop distinctive hunting methods, vocal traditions, and social behaviors, leading researchers to describe regional ecotypes and cultures.
The genus Orcinus also contains fossil species, including Orcinus citoniensis and Orcinus paleorca, but only Orcinus orca survives today. “Killer whale” is therefore not a separate species from “orca”; both names refer to the same living animal. The name “orca” is the accepted common-name answer, while Orcinus orca is the full scientific form.