FUNCTIONAL SUBDIVISION OF THE VERTEBRAL COLUMN IN FOUR SOUTH AMERICAN DOLPHINS

MARÍA CONSTANZA MARCHESI; MATÍAS SEBASTIÁN MORA; ENRIQUE ALBERTO CRESPO; CLAUDIA C. BOY; ROLANDO GONZÁLEZ-JOSÉ; RAE NATALIE P. GOODALL

MASTOZOOLOGí­A NEOTROPICAL

UNIDAD DE ZOOLOGÍA Y ECOLOGÍA ANIMAL, INSTITUTO ARGENTINO DE INVESTIGACIÓN DE LAS ZONAS ARIDAS, CRICYT, CONICET

Lugar: Mendoza; Año: 2019

0327-9383

Description and functional interpretation of morphological variation in the dolphin column can be facilitated by recognizing structural units. This information offers important clues to the proportion of the column involved in the oscillation and displacement of the flukes, and how swimming style can vary among species. Thus, the morphological characterization and functional subdivision of the vertebral column is of key importance to gain insights into the locomotor performance of cetacean species occurring in different environments. We employed traditional morphometrics to establish the functional subdivision of the vertebral column of Commerson?s dolphin (Cephalorhynchus commersonii), a coastal species, and the dusky dolphin (Lagenorhynchus obscurus), a shelf species. These species are closely related, and some of them are partially sympatric. We also compared the obtained results against information previously reported by Marchesi et al (2017) on Peale?s dolphin (Lagenorhynchus australis), a coastal species, and the hourglass dolphin (Lagenorhynchus cruciger), an oceanic species. These results bring further support to our hypothesis that coastal species have morphological traits associated with higher flexibility, whilst platform and oceanic species have features associated with higher stability in a greater proportion of their column.