据估计，南极周围大约有 25，000只逆戟鲸，有四种类型被记录在案。苏联研究人员在 1980年代描述了两个矮小物种，名为Orcinus nanus和Orcinus glacialis，但大多数鲸类研究人员对它们的地位持怀疑态度，并且很难将它们与下述类型直接联系起来。

逆戟鲸变异的一些例子

A型或南极逆戟鲸看起来像“典型”逆戟鲸，体型庞大，黑白相间，眼罩中等大小，生活在开阔水域，主要以小须鲸为食。

B1型或浮冰虎鲸比 A型小。它有一个大的白色眼罩。它身体的大部分深色部分是中灰色而不是黑色，尽管它有一块深灰色斑块，称为“背角”，从前额一直延伸到背鳍的后面。白色区域染成淡黄色。它主要以海豹为食。B1型逆戟鲸在阿德莱德岛和南极半岛大陆之间大量存在。

B2型或Gerlache逆戟鲸在形态上与 B1型相似，但更小。这种生态型已被记录为以企鹅和海豹为食，并且经常在Gerlache海峡发现。

C型或罗斯海虎鲸是最小的生态型，并且比其他虎鲸生活在更大的群体中。它的眼罩明显向前倾斜，而不是平行于身体轴线。和 B型一样，它主要是白色和中灰色，有深灰色的背披和黄色斑块。它唯一观察到的猎物是南极鳕鱼。

根据 1955年在新西兰大规模搁浅的照片以及自 2004年以来的六次海上目击事件， D型或亚南极逆戟鲸首次被识别出来。这种类型的第一个视频记录是在 2014年在凯尔盖朗群岛和克罗泽群岛之间拍摄的，并且再次2017年在智利合恩角海岸外。它可以通过白色的小眼罩、比通常的背鳍更窄更短、球状头部（类似于领航鲸）和更小的牙齿来识别。它的地理范围似乎在南纬40°S和60°S之间的亚南极海域环绕全球.虽然它的饮食尚未确定，但根据延绳钓船只周围的照片确定，它可能包括鱼类，其中 D型逆戟鲸似乎正在捕食巴塔哥尼亚齿鱼( Dissostichus eleginoides )。

B型和 C型生活在靠近冰的地方，这些水域中的硅藻可能是这两种类型的淡黄色的原因。线粒体 DNA序列支持这些是最近分化的独立物种的理论。最近，完整的线粒体测序表明 B型和 C型被认为是不同的物种，北太平洋的瞬变物种也应如此，而将其他物种作为亚种等待更多数据。对整个线粒体基因组进行测序的先进方法揭示了不同人群之间 DNA的系统差异。2019年对 D型虎鲸的一项研究还发现，它们与其他种群不同，甚至可能是一个独特的物种。

英文原文：

Orcas or killer whales have a cosmopolitan distribution and several distinct populations or types have been documented or suggested. Three to five types of orcas may be distinct enough to be considered different races， subspecies， or possibly even species (see Species problem). The IUCN reported in 2008，“The taxonomy of this genus is clearly in need of review， and it is likely that O. orca will be split into a number of different species or at least subspecies over the next few years.“ Although large variation in the ecological distinctiveness of different orca groups plicate simple differentiation into types. Mammal-eating orcas in different regions were long thought likely to be closely related， but genetic testing has refuted this hypothesis.

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Northern waters

North Pacific

Research off the west coast of Canada and the United States in the 1970s and 1980s identified the following three types:

Resident (fish-eating) orcas: The curved dorsal fins are typical of resident females.

Resident: These are the most monly sighted of the three populations in the coastal waters of the northeast Pacific. Residents' diets consist primarily of fish and sometimes squid， and they live in plex and cohesive family groups called pods. Female residents characteristically have rounded dorsal fin tips that terminate in a sharp corner. They visit the same areas consistently. British Columbia and Washington resident populations are amongst the most intensively studied marine mammals anywhere in the world. Resident orcas can be divided into at least three distinct munities; northern， southern and southern Alaskan. Southern Alaskan resident orcas are distributed from southeastern Alaska to the Kodiak Archipelago and number over 700 individuals. These whales consist of two interbreeding clans distinguished by acoustic calls and whose ranges overlap. The northern resident munity lives in coastal and inland waters from southeastern Alaska to Vancouver Island. It consists of three clans and 16 pods and number over 300 orcas total. The southern resident munity generally inhabits the inland waters of southern British Columbia and Washington， but can be found in the outer waters off Vancouver Island， Washington， Oregon and California. They consist of one clan and three pods， and number less than 80 individuals and are listed as endangered.

Transient or Bigg's: The diets of these orcas consist almost exclusively of marine mammals. They live in the same areas as residents， but the two avoid each other. Transients generally travel in small groups， usually of two to six animals， and have less persistent family bonds than residents. Transients vocalize in less variable and less plex dialects. Female transients are characterized by more triangular and pointed dorsal fins than those of residents. The grey or white area around the dorsal fin， known as the “saddle patch“， often contains some black colouring in residents. However， the saddle patches of transients are solid and uniformly grey. Transients roam widely along the coast; some individuals have been sighted in both southern Alaska and California. Transients are also referred to as Bigg's orca in honour of cetologist Michael Bigg. The term has bee increasingly mon and may eventually replace the transient label. The transient ecotype is estimated to have diverged 700，000 years ago. There are at least three different “stocks“ of transients off North America， the AT1 stock which occurs from Prince William Sound to Kenai Fjords， the Gulf of Alaska/Aleutian Islands/Bering Sea (GOA/AI/BS) stock and the west coast stock which ranges from southeast Alaska to California. AT1 is considered a depleted stock; it was affected by the Exxon Valdez oil spill and declined from 22 individuals to eight between 1989 and 2004. The GOA/AI/BS stock may number around 500 whales while the west coast transients number over 320 orcas with over 200 along southeast Alaska， British Columbia and Washington and over 100 orcas off California. California transients do not appear to intermingle much with those further north and west coast transients may be divided into sub-munities.

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Offshore: A third population of orcas in the northeast Pacific was discovered in 1988， when a humpback whale researcher observed them in open water. As their name suggests， they travel far from shore and feed primarily on schooling fish. However， because they have large， scarred and nicked dorsal fins resembling those of mammal-hunting transients， it may be that they also eat mammals and sharks. They have mostly been encountered off the west coast of Vancouver Island and near Haida Gwaii. Offshores typically congregate in groups of 20–75， with occasional sightings of larger groups of up to 200. Little is known about their habits， but they are genetically distinct from residents and transients. Offshores appear to be smaller than the others， and females are characterized by dorsal fin tips that are continuously rounded.

Separate fish-eating and mammal-eating orca munities also exist off the coast of the Russian Far East and Hokkaido， Japan. Russian orcas are monly seen around the Kamchatka Peninsula and Commander Islands. Over 2，000 individual resident-like orcas and 130 transient-like orcas have been identified off Russia. At least 195 individual orcas have been cataloged in the eastern tropical Pacific， ranging from Baja California and the Gulf of California in the north to the northwest coast of South America in the south and west towards Hawaii. Orcas appear to regularly occur off the Galápagos Islands. Orcas sighted in Hawaiian waters may belong to a greater population in the central Pacific.

North Atlantic and adjacent

Orca tail-slapping in Vestfjorden， Norway