|Background: Minke whales are separated into two genetically distinct species: the Antarctic minke whale found in
the southern hemisphere, and the common minke whale which is cosmopolitan. The common minke whale is
further divided into three allopatric sub-species found in the North Pacific, southern hemisphere, and the North
Atlantic. Here, we aimed to identify the genetic ancestry of a pregnant female minke whale captured in the North
Atlantic in 2010, and her fetus, using data from the mtDNA control region, 11 microsatellite loci and a sex
Results: All statistical parameters demonstrated that the mother was a hybrid displaying maternal and paternal
contribution from North Atlantic common and Antarctic minke whales respectively. Her female fetus displayed
greater genetic similarity to North Atlantic common minke whales than herself, strongly suggesting that the hybrid
mother had paired with a North Atlantic common minke whale.
Conclusion: This study clearly demonstrates, for the first time, that hybrids between minke whale species may be
fertile, and that they can back-cross. Whether contact between these species represents a contemporary event
linked with documented recent changes in the Antarctic ecosystem, or has occurred at a low frequency over many
years, remains open.