Ana Galov: Genetic diversity of bottlenose dolphin (Tursiops truncatus) and notes on genetic diversity of other cetacean species in the Adriatic Sea. Dissertation. Faculty of Science University of Zagreb. Zagreb. 2007.

 

Abstract

The bottlenose dolphin (Tursiops truncatus) is the only resident marine mammal species in Croatian part of the Adriatic Sea, with number estimated at 220 to 250 individuals. It is endangered and legally protected species in Croatia. Although a general concern for the conservation of endangered species is the maintenance of genetic variation within populations, no research has been done on genetic variation of any cetacean species in Croatia, up to now. In this thesis 34 bottlenose dolphin samples from Croatia, five from Israel, 12 striped dolphin (Stenella coeruleoalba), five Risso's dolphin {Grampus griseus), a Cuvier's beaked whale (Ziphius caxirosths) and two fin whale (Balaenoprera physalus) samples were analysed by twelve microsatellite loci (EV1, EV14, EV37, EV94,' TexVet3, TexVetf, TexVet7, D08, D14, D18, D22, D28) and 470bp fragment of the mitochondrial DNA control region. Gene diversity for Croatian population of bottlenose dolphin is relatively high (0.669). Deviation from 11W equilibrium was detected only in locus D28. Other loci did not show deviation from 1IWE, suggesting panmixia in population. No evidence of bottleneck was found. Analysis of molecular variance indicated that 11% of the variance was among Croatian and Israeli populations and only 5.6% of the variance was among northern and southern regions of the Adriatic. Haplotype diversity of Croatian bottlenose dolphin population is relatively low (0,557), but the nucleotide diversity is relatively high (0,022), as opposed to haplotype diversity (0,667) and nucleotide diversity (0,007) of striped dolphin. In both species five unique haplotypes were found. No congruence between topology of bottlenose dolphin genealogy tree and geographic origin of the samples was found. All microsatellite loci and all but TV5 were successfully amplified in striped and Risso's dolphin, respectively and all loci were polymorphic.