John Y Wang1,2,3, Shih Chu Yang4, Samuel K Hung5. 1. CetAsia Research Group, Thornhill, Ontario L4J-7X1, Canada. 2. Department of Biology, Trent University, Peterborough, Ontario K9J-7B8, Canada. 3. National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan. 4. FormosaCetus Company Ltd, Hualien 970, Taiwan. 5. Hong Kong Cetacean Research Project, Lam Tin, Kowloon, Hong Kong, China.
Abstract
BACKGROUND: Subspecies recognition can affect how people (scientists and non-scientists alike) view organisms and thus has important implications for research on, as well as the conservation of, these entities. Recently, a small group of Indo-Pacific humpback dolphins was discovered inhabiting the waters off central western Taiwan. This geographically isolated population possesses pigmentation patterns that are subtly, but noticeably, different from their nearest conspecifics in the neighbouring waters of the Jiulong River Estuary and Pearl River Estuary of mainland China. Due to this population's low and declining numbers and the numerous threats it faces, it was assessed as critically endangered by the Red List of Threatened Species of the International Union for Conservation of Nature. The purpose of this study is to examine the degree of differentiation of the Taiwanese population to determine if subspecies recognition iswarranted. RESULTS: Analysis of the degree of differentiation in pigmentation patterns revealed nearly non-overlapping distributions between dolphins from Taiwanese waters and those from the Jiulong River + Pearl River estuaries of mainland China (the nearest known populations). The Taiwanese dolphins were clearly diagnosable from those of the Jiulong River + Pearl Riverestuaries under the most commonly accepted '75%rule' for subspecies delimitation (with 94% of one group being separable from 99+% of the other). Evidence of geographical isolation and behavioural differences also provided additional support for the distinctiveness of the Taiwanese dolphins. CONCLUSIONS: Together, the evidence strongly demonstrated that the Taiwanese humpback dolphin population is differentiated at the subspecies level and on an evolutionary trajectory that is independent from that of dolphins from adjacent waters of mainland China (i.e. Jiulong River + Pearl River estuaries). As a result, the taxonomy of Sousa chinensis was revised to include two subspecies: the Taiwanese humpback dolphin, Sousa chinensis taiwanensis subsp. nov., and the Chinese humpback dolphin, Sousa chinensis chinensis (the nominotypical subspecies). These subspecies are described, and the holotype and paratype specimens for S. c. taiwanensis are established.
BACKGROUND: Subspecies recognition can affect how people (scientists and non-scientists alike) view organisms and thus has important implications for research on, as well as the conservation of, these entities. Recently, a small group of Indo-Pacific humpback dolphins was discovered inhabiting the waters off central western Taiwan. This geographically isolated population possesses pigmentation patterns that are subtly, but noticeably, different from their nearest conspecifics in the neighbouring waters of the Jiulong River Estuary and Pearl River Estuary of mainland China. Due to this population's low and declining numbers and the numerous threats it faces, it was assessed as critically endangered by the Red List of Threatened Species of the International Union for Conservation of Nature. The purpose of this study is to examine the degree of differentiation of the Taiwanese population to determine if subspecies recognition iswarranted. RESULTS: Analysis of the degree of differentiation in pigmentation patterns revealed nearly non-overlapping distributions between dolphins from Taiwanese waters and those from the Jiulong River + Pearl River estuaries of mainland China (the nearest known populations). The Taiwanese dolphins were clearly diagnosable from those of the Jiulong River + Pearl Riverestuaries under the most commonly accepted '75%rule' for subspecies delimitation (with 94% of one group being separable from 99+% of the other). Evidence of geographical isolation and behavioural differences also provided additional support for the distinctiveness of the Taiwanese dolphins. CONCLUSIONS: Together, the evidence strongly demonstrated that the Taiwanese humpbackdolphin population is differentiated at the subspecies level and on an evolutionary trajectory that is independent from that of dolphins from adjacent waters of mainland China (i.e. Jiulong River + Pearl River estuaries). As a result, the taxonomy of Sousa chinensis was revised to include two subspecies: the Taiwanese humpbackdolphin, Sousa chinensis taiwanensis subsp. nov., and the Chinese humpbackdolphin, Sousa chinensis chinensis (the nominotypical subspecies). These subspecies are described, and the holotype and paratype specimens for S. c. taiwanensis are established.
Authors: Susan M Haig; Erik A Beever; Steven M Chambers; Hope M Draheim; Bruce D Dugger; Susie Dunham; Elise Elliott-Smith; Joseph B Fontaine; Dylan C Kesler; Brian J Knaus; Iara F Lopes; Pete Loschl; Thomas D Mullins; Lisa M Sheffield Journal: Conserv Biol Date: 2006-12 Impact factor: 6.560
Authors: Martin Mendez; Thomas A Jefferson; Sergios-Orestis Kolokotronis; Michael Krützen; Guido J Parra; Tim Collins; Giana Minton; Robert Baldwin; Per Berggren; Anna Särnblad; Omar A Amir; Vic M Peddemors; Leszek Karczmarski; Almeida Guissamulo; Brian Smith; Dipani Sutaria; George Amato; Howard C Rosenbaum Journal: Mol Ecol Date: 2013-10-29 Impact factor: 6.185