Vertebral column deformities in white-beaked dolphins from the eastern North Atlantic.

Cg Bertulli,Cc Kinze,A Galatius,P Jepson,A Watson,Gj Sánchez Contreras,Mh Rasmussen,Rc Sabin,Ej Vedder,R Deaville

doi:10.3354/dao02904

Abstract

Five white-beaked dolphins Lagenorhynchus albirostris with outwardly vertebral kyphosis, kyphoscoliosis or lordosis were identified during a photo-identification survey of over 400 individuals (2002-2013) in Faxaflói and Skjálfandi Bays, Iceland. In addition, 3 stranding reports from Denmark, The Netherlands and the UK were analysed, providing both external observation and post mortem details of axial deviations of the vertebral column in this species. Two of the free-ranging cases and 2 of the stranded specimens appeared to have an acquired disease, either as a direct result of trauma, or indirectly from trauma/wound and subsequent infection and bony proliferation, although we were unable to specifically identify the causes. Our data represent a starting point to understand vertebral column deformations and their implications in white-beaked dolphins from the eastern North Atlantic. We recommend for future necropsy cases to conduct macro- and microscopic evaluation of muscle from both sides of the deformed region, in order to assess chronic or acute conditions related to the vertebral deformations and cause of death.

Highlights

Axial deviations of the vertebral column have been reported in several delphinid species (e.g. Nutman & Kirk 1988, Wilson et al 1997, Berghan & Visser 2000, Watson et al 2004, Berrow & O’Brien 2006, Van Bressem et al 2006, Bearzi et al 2009, DeLynn et al 2011, Robinson 2014)
Five white-beaked dolphins Lagenorhynchus albirostris with outwardly vertebral kyphosis, kyphoscoliosis or lordosis were identified during a photo-identification survey of over 400 individuals (2002−2013) in Faxaflói and Skjálfandi Bays, Iceland
Such deformities are usually described within 3 categories: (1) kyphosis — abnormal deviation of the vertebral column in a sagittal plane when vertebrae are fixed to produce a curvature of the vertebral column with concavity on the ventral side; (2) lordosis

Summary

Introduction

Axial deviations of the vertebral column have been reported in several delphinid species (e.g. Nutman & Kirk 1988, Wilson et al 1997, Berghan & Visser 2000, Watson et al 2004, Berrow & O’Brien 2006, Van Bressem et al 2006, Bearzi et al 2009, DeLynn et al 2011, Robinson 2014) They can be classified as deformities arising from congenital causes (e.g. bottlenose dolphin Tursiops truncatus with congenital scoliosis, DeLynn et al 2011) or that have been acquired following trauma (e.g. bottlenose dolphin with kyphosis due to conspecific aggression, Watson et al 2004). Dis Aquat Org 116: 59–67, 2015 kyphosis) — abnormal deviation of the vertebral column in a sagittal plane when vertebrae are fixed to produce a curvature of the vertebral column with concavity on the dorsal side; (3) scoliosis — abnormal deviation of the vertebral column in a dorsal plane so the vertebrae are fixed to produce a lateral curvature, possibilities of left- and/or right-sided curvatures These deformities are often present in varying combinations. We review 8 cases of such deformities in white-beaked dolphins from Iceland, the UK, Denmark and The Netherlands

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