Dear All,
On behalf of my co-authors, I am pleased to share our recent paper published first online in the Zoological Journal of the Linnean Society. In this study we describe a species of bottlenose dolphin for the coastal waters of the US Atlantic Ocean based on an integrative taxonomic approach. We resurrected the name Tursiops erebennus and suggested the common name Tamanend’s bottlenose dolphin for this coastal bottlenose dolphin species:
Costa APB, McFee W, Wilcox LA, Archer FI, Rosel PE. 2022. The common bottlenose dolphin (Tursiops truncatus) ecotypes of the western North Atlantic revisited: an integrative taxonomic investigation supports the presence of distinct species. Zoological Journal of the Linnean Society. https://doi.org/10.1093/zoolinnean/zlac025
Abstract
Integrative taxonomy can help us to gain a better understanding of the degree of evolutionary divergence between taxa. In the western North Atlantic (wNA), two ecotypes (coastal and offshore) of common bottlenose dolphin, Tursiops truncatus, exhibit some external morphological differences, and previous genetic findings suggested that they could be different species. However, their taxonomy remains unsettled. Using an integrative approach comparing traditional and geometric morphometrics, mitochondrial and nuclear DNA, we evaluated evolutionary relationships between these ecotypes. We observed congruence among these lines of evidence, strongly indicating that the wNA ecotypes are following distinct evolutionary trajectories. Based on mitochondrial DNA analyses, we detected significant divergence (Nei’s dA = 0.027), unshared haplotypes and one fixed difference leading to complete diagnosability (percentage diagnosable = 100%) of the wNA coastal ecotype. We found morphological diagnosability and negligible nuclear gene flow between the wNA ecotypes. Integration of these multiple lines of evidence revealed that the wNA coastal ecotype is an independent evolutionary unit, appearing to be more closely related to coastal dolphins in the Gulf of Mexico and Caribbean Sea than to their parapatric offshore neighbours, while the offshore dolphins form a relatively cohesive worldwide unit, T. truncatus. We propose that this coastal ecotype is recognized as a distinct species, resurrecting the name Tursiops erebennus.
Best,
Ana