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