Ana Galov: Genetic diversity of bottlenose dolphin (Tursiops
truncatus) and notes on genetic diversity of other cetacean species in the
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.