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, 6 (9), e24047

A New Dolphin Species, the Burrunan Dolphin Tursiops Australis Sp. Nov., Endemic to Southern Australian Coastal Waters

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A New Dolphin Species, the Burrunan Dolphin Tursiops Australis Sp. Nov., Endemic to Southern Australian Coastal Waters

Kate Charlton-Robb et al. PLoS One.

Abstract

Small coastal dolphins endemic to south-eastern Australia have variously been assigned to described species Tursiops truncatus, T. aduncus or T. maugeanus; however the specific affinities of these animals is controversial and have recently been questioned. Historically 'the southern Australian Tursiops' was identified as unique and was formally named Tursiops maugeanus but was later synonymised with T. truncatus. Morphologically, these coastal dolphins share some characters with both aforementioned recognised Tursiops species, but they also possess unique characters not found in either. Recent mtDNA and microsatellite genetic evidence indicates deep evolutionary divergence between this dolphin and the two currently recognised Tursiops species. However, in accordance with the recommendations of the Workshop on Cetacean Systematics, and the Unified Species Concept the use of molecular evidence alone is inadequate for describing new species. Here we describe the macro-morphological, colouration and cranial characters of these animals, assess the available and new genetic data, and conclude that multiple lines of evidence clearly indicate a new species of dolphin. We demonstrate that the syntype material of T. maugeanus comprises two different species, one of which is the historical 'southern form of Tursiops' most similar to T. truncatus, and the other is representative of the new species and requires formal classification. These dolphins are here described as Tursiops australis sp. nov., with the common name of 'Burrunan Dolphin' following Australian aboriginal narrative. The recognition of T. australis sp. nov. is particularly significant given the endemism of this new species to a small geographic region of southern and south-eastern Australia, where only two small resident populations in close proximity to a major urban and agricultural centre are known, giving them a high conservation value and making them susceptible to numerous anthropogenic threats.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Graphic analyses on cranial morphology delineating Tursiops australis sp. nov. and Tursiops species (A–B).
Red = Group 1: Tursiops australis sp. nov., blue = Group 2: T. truncatus, green = Group 3: T. aduncus. Individuals with known mtDNA sequence are indicated by★with the appropriate species colour code. (A) Hierarchical multivariate cluster analysis on cranial morphological traits showing three highly supported groups (cophenetic correlation 0.8337). Tursiops australis sp. nov. holotype (QVMAG#1365) in Group 1, and Tursiops maugeanus male (QVMAG#1360) in Group 2. (B) Discriminant function analyses scatterplot of canonical scores on cranial morphological traits delineating Tursiops australis sp. nov., T. truncatus and T. aduncus.
Figure 2
Figure 2. Graphic analyses on external morphology delineating Tursiops australis sp. nov. and Tursiops truncatus (A–B).
Red = Group 1: Tursiops australis sp. nov., blue = Group 2: T. truncatus. Individuals with known mtDNA sequence are indicated by★with the appropriate species colour code. (A) Hierarchical multivariate cluster analysis on external morphological traits showing two highly supported groups (cophenetic correlation of 0.747). (B) Discriminant function analyses on external morphological traits delineating Tursiops australis sp. nov. and T. truncatus (Hotellings t2: p = 0.0224).
Figure 3
Figure 3. Phylogenetic analysis of the mtDNA control region haplotypes (A–B).
Haplotypes specific to the study are denoted by ★ red = Tursiops australis sp. nov., blue = T. truncatus. (A) Consensus tree obtained by Maximum Likelihood and Neighbour-joining methods from mtDNA control region haplotypes. Tree is rooted with the outgroup Lagenorhynchus acutus. Bootstrap values >50% are indicated (1000 replicates: ML left value; NJ right value)(intra-species specific values not reported). (B) Majority rule consensus tree from Bayesian reconstruction (MrBayes) with posterior probabilities branch support values.
Figure 4
Figure 4. Direct visual comparison of cranial morphology (A–C).
Tursiops truncatus (a: representing Group 2 of multivariate analyses QVMAG#1360, as lectotype of T. maugeanus); and Tursiops australis sp. nov. (b: representing Group 1of multivariate analyses QVMAG #1365, holotype). (A) Skulls are shown in dorsal view, note maxilla- premaxilla. (B) Ventral view, location of pterygoids and palatine noted (shown magnified in C). (C) Views of the pterygoids and palatine regions red = palatine length, blue = palatine suture angle.
Figure 5
Figure 5. Tursiops australis sp. nov. external morphology and colouration (A–C).
(A and B) Distinct tri-colouration, extension of ventrum white above eye, dorsal blaze, ‘stubby’ rostrum and falcate dorsal fin. (C) View of ‘stubby’ rostrum.

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References

    1. Steeman ME, Hebsgaard MB, Fordyce RE, Ho SYW, Rabosky DL, et al. Radiation of Extant Cetaceans Driven by Restructuring of the Oceans. Systematic Biology. 2009;58:573–585. - PMC - PubMed
    1. Caballero S, Trujillo F, Vianna JA, Barrios-Garrido H, Montiel MG, et al. Taxonomic status of the genus Sotalia: Species level ranking for “tucuxi” (Sotalia fluviatilis) and “costero” (Sotalia guianensis) dolphins. Marine Mammal Science. 2007;23:358–386.
    1. Beasley I, Robertson KM, Arnold P. Description of a new dolphin, the Australian Snubfin dolphin Orcaella heinsohni sp. n. (Cetacea, Delphinidae). Marine Mammal Science. 2005;21:365–400.
    1. Kingston SE, Adams LD, Rosel PE. Testing mitochondrial sequence and anonymous nuclear markers for phylogeny reconstruction in a rapidly radiating group: molecular systematics of the Delphininae (Ceatcea: Odontoceti: Delphinidae). BMC Evolutionary Biology. 2009;9:245. - PMC - PubMed
    1. LeDuc RG, Perrin WF, Dizon AE. Phylogenetic relationships among the delphinid cetaceans based on full cytochrome b sequences. Marine Mammal Science. 1999;15:619–648.

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