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Mitochondrial DNA analysis of sympatric morphotypes of bottlenose dolphins (genus: Tursiops ) in Chinese waters
Author(s) -
Wang J. Y.,
Chou L.S.,
White B. N.
Publication year - 1999
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1046/j.1365-294x.1999.00741.x
Subject(s) - sympatric speciation , biology , sympatry , bottlenose dolphin , zoology , mitochondrial dna , genus , reproductive isolation , phylogenetic tree , ecology , genetics , population , demography , sociology , gene
The classification within the bottlenose dolphin (genus Tursiops ) is controversial. Although many morphological variants exist, most authors have concluded that the genus is composed of a single species, Tursiops truncatus (Montagu 1821). Two distinct morphotypes of bottlenose dolphins, which have been referred to as T. truncatus and T. aduncus , exist in sympatry in Chinese waters. Comparisons of a 386‐bp fragment of the mitochondrial DNA (mtDNA) control region ( n = 47) indicated that the two sympatric morphotypes were genetically distinct, with seven fixed site differences and a sequence divergence of approximately 4.4%. Phylogenetic analyses using maximum likelihood, neighbour‐joining and maximum parsimony approaches showed that the truncatus ‐type dolphins from Chinese waters were more closely related to Atlantic Ocean truncatus ‐type than to the sympatric aduncus ‐type dolphins. The Atlantic truncatus ‐type dolphins also shared the same diagnostic sites that separated Chinese truncatus ‐type from aduncus ‐type dolphins. The molecular data agreed completely with the morphological classifications of the specimens. This congruence is strong evidence that the sympatric morphotypes in Chinese waters are reproductively isolated and comprise two distinct species. These findings have important implications for the conservation of bottlenose dolphins in Chinese waters.