Darinka Škrtić: Skeletal anatomical variations and patho-anatomical lesions in the bottlenose dolphin (Tursiops truncatus Montagu 1821) from the Adriatic Sea. Dissertation. Faculty of Veterinary Medicine University of Zagreb. Zagreb. 2010.



The bottlenose dolphin (Tursiops truncatus) is today the only resident marine mammal in the Adriatic Sea and is a legally protected species. This study included 116 bottlenose dolphins found dead from 1990 to January 2009 in Croatian part of the Adriatic Sea. Their skeletal remains are kept at the Department of Anatomy, Histology and Embryology of the Faculty of Veterinary Medicine, University of Zagreb. For the purpose of this study the skeletons were macroscopically inspected and every skeletal variation and lesion was described and photographed. The data of the animals (sex, age and body measurements) were taken from the database of the collection and used in the correlation analysis. Skeletal anatomical variations and patho-anatomical lesions were observed in 74 (63.8%) bottlenose dolphins while 42 (36.2%) animals did not show any variations from the usual bottlenose dolphin skeletal morphology. Osteoarthritis deformans was the major skeletal lesion on the skull (in 19.6% animals). Ankylosing spondiloarthrosis was the most frequently observed skeletal lesion on cervical vertebra (in 29.4% animals). Thickening and lateral flexion of the spinal process was the major skeletal lesion in the thoracic vertebra (in 16.8% of the animals), which was frequently observed also in the lumbar (29.4%) and caudal (50.4%) vertebra. Skeletal lesions were more frequently observed in caudal vertebra compared to other vertebral groups. Rib fractures are frequently observed (in 22.4% animal) and mainly in males. Anatomical variations of the sternum were observed in 18.2% of animals. Scapula shows frequently lesions at glenoid cavity (26.6%), and the humerus at the head (osteoarthritis cavitas glenoidalis et caput humeri). Scapula was fractured in 2.8% animals. Distal parts of the flipper did not show any skeletal variations or lesions. The observed skeletal anatomical variations and patho-anatomical lesions in bottlenose dolphins from Croatian part of the Adriatic Sea, are related to different etiologies which have to be part of future research on this protected marine mammal.