FUNCTIONAL SUBDIVISION OF THE VERTEBRAL COLUMN IN FOUR SOUTH AMERICAN DOLPHINS

MARIA CONSTANZA MARCHESI; MATÍAS MORA; ENRIQUE CRESPO; CLAUDIA BOY; ROLANDO GONZÁLEZ-JOSÉ

MASTOZOOLOGí­A NEOTROPICAL

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

Lugar: Mendoza; Año: 2018

0327-9383

Description and functional interpretation of morphological variation in the dolphin column can be facilitated by recognizing structural units along its whole structure. This information offers important clues to the proportion of the column involved in the oscillation and displacement of the flukes, and how the 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. Species studied here are closely related and, in some cases, are partially sympatric. We employed traditional morphometrics to establish the functional subdivision of the vertebral column of the Commerson?s dolphin (Cephalorhynchus commersonii), a coastal species, and the dusky dolphin (Lagenorhynchus obscurus), a shelf species. We also compared the obtained results against information previously reported by Marchesi et al (2017) on the 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.