engleski

The prevalence of congenital umbilical hernia in bottlenose dolphins (Tursiops truncatus) in the Adriatic

Congenital umbilical hernia is a malformation of the ventral abdominal wall of animals and humans. In terrestrial species, such malformation causes death in-utero or soon after birth. To our knowledge there are no data on the incidence of this malformation in the bottlenose dolphins (Tursiops truncatus) in the literature. In humans, the congenital umbilical hernias appear in 3.5 out of 10, 000 cases of normal births. The bottlenose dolphin is the only resident marine mammal species in the Croatian part of the Adriatic Sea, with an estimated number of around 200 adult individuals and around 20 cubs living in the area. It is estimated that between 15 and 20 bottlenose dolphin births occur there annually. We examined 123 carcasses of bottlenose dolphins found in the Croatian part of the Adriatic Sea since 1990. The congenital umbilical hernia was found in 13 cases (five of them were either foetuses found in uteruses of dead mothers or aborted foetuses ; while 8 were born alive and lived for various periods of time). The estimated total number of births of bottlenose dolphins in the Croatian part of the Adriatic Sea since 1990 is between 270 and 360. This means that congenital umbilical hernia appears in between 361 and 482 out of 10, 000 cases of normal births of bottlenose dolphins in the Adriatic. Our findings indicate that the incidence of congenital umbilical hernia in the Adriatic bottlenose dolphins is more than 100 times higher than that recorded in humans. The cause of such high incidence in the bottlenose dolphin remains unknown. Our future research will focus on determining a degree of relatedness among affected animals using molecular markers, in which we would test the hypothesis of the genetic basis of this malformation in the bottlenose dolphin. Furthermore, we do not know whether such high incidence of congenital umbilical hernia is found only in the Adriatic population of the bottlenose dolphin, or is it inherent to the bottlenose dolphin species.

bottlenose dolphin

nije evidentirano