Genetic and Photogrammetric Investigations of Three Ecotypes of Killer Whales in the Southern Ross Sea

关于虎鲸系统学和生态学的信息目前是在单一、混合物种的概念框架内解释的。然而，最近的证据表明，三种不同形式的虎鲸(Orcinus sp.)发生在南极洲的南极洲。这些种类有不同的猎物和栖息地偏好，不同的平均学校规模和地理分布，以及不同的形态，因此建议最好将它们视为独立的物种。所有这三种形态都出现在罗斯海，研究人员建议评估独立物种假说。如果南极水域确实存在三个不同的物种，那么拟议工作的结果有可能在很大程度上重塑我们对南极洲虎鲸生态和保护状况的理解。鉴于虎鲸的大量数量(目前估计为25,000-94,000头)和顶级营养级捕食者的地位，虎鲸无疑是南极生态系统中的关键物种，但在其分类地位得到澄清之前，人们无法了解它们的作用。此外，虎鲸的养护状况，包括商业捕捞的潜在影响，取决于适当地确定它们的分类地位、具体说明饮食需求和评估渔业的影响。提出了两个主要目标：(1)比较三种形式之间的遗传差异；(2)准确确定用于形态比较的长度和体型比例。虎鲸可以说是地球上最知名、研究最深入的大型动物之一，但关于生态系统中有多少物种以及它们如何发挥作用的基本问题仍然没有答案。确认南极水域的新物种将突显这样一个事实，即我们对海洋生物多样性的了解可能比目前所认识的更加初级。

Information on killer whale systematics and ecology is currently interpreted within the conceptual framework of a single, intermixing species. However, recent evidence suggests that three distinct forms of killer whales (Orcinus sp.) occur in Antarctica during the austral summer. These forms have different prey and habitat preferences, different average school sizes and geographic distributions, and distinct morphologies, and therefore it was suggested that they are best regarded as separate species. All three forms occur in the Ross Sea and the investigators propose to evaluate the separate species hypothesis. If, in fact, there are three distinct species in Antarctic waters, results of the proposed work have the potential to largely re-shape our understanding of killer whale ecology and conservation status in Antarctica. Given their large numbers (current estimates: 25,000-94,000) and status as top trophic level predators, killer whales are undoubtedly key species in the Antarctic ecosystem but their roles will not be understood until their taxonomic status is clarified. Also, the conservation status of killer whales, including potential effects of commercial fishing, depends on properly identifying their taxonomic status, specifying dietary needs, and assessing the impacts of fisheries. Two main goals are proposed: (1) to compare genetic divergence among the three forms and (2) to accurately determine lengths and body proportions for morphological comparisons. The killer whale is arguably one of the most recognizable, and best-studied, large animals on earth, yet basic questions about how many species there are and how they function within the ecosystem remain unanswered. Confirming new species in Antarctic waters would highlight the fact that our knowledge of marine biodiversity is perhaps even more rudimentary than currently recognized.