Mitogenomes and relatedness do not predict frequency of tool-use by sea otters.
Many ecological aspects of tool-use in sea otters are similar to those in Indo-Pacific bottlenose dolphins. Within an area, most tool-using dolphins share a single mitochondrial haplotype and are more related to each other than to the population as a whole. We asked whether sea otters in California showed similar genetic patterns by sequencing mitogenomes of 43 otters and genotyping 154 otters at 38 microsatellite loci. There were six variable sites in the mitogenome that yielded three haplotypes, one found in only a single individual. The other two haplotypes contained similar percentages (33 and 36%) of frequent tool-users and a variety of diet types. Microsatellite analyses showed that snail specialists, the diet specialist group that most frequently used tools, were no more related to each other than to the population as a whole. The lack of genetic association among tool-using sea otters compared with dolphins may result from the length of time each species has been using tools. Tool-use in dolphins appears to be a relatively recent innovation (less than 200 years) but sea otters have probably been using tools for many thousands or even millions of years.
Center for Conservation Genomics, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA rallsk@thegrid.net.
Katherine
K
Ralls
Center for Conservation Genomics, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA.
Nancy Rotzel
NR
McInerney
Wildlife Genomics and Disease Ecology, Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82071, USA.
Roderick B
0000-0002-4901-5081
RB
Gagne
Wildlife Genomics and Disease Ecology, Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82071, USA.
Holly B
0000-0002-0205-8818
HB
Ernest
US Geological Survey, Western Ecological Research Center, Santa Cruz, CA 95060, USA.
M Tim
MT
Tinker
Monterey Bay Aquarium, Monterey, CA 93940, USA.
Jessica
J
Fujii
Center for Conservation Genomics, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA.
Jesus
J
Maldonado
D000818:Animals; D002140:California; D004032:Diet / Q000662:veterinary; D054629:Genome, Mitochondrial; D006239:Haplotypes; D018895:Microsatellite Repeats; D010041:Otters / Q000235:genetics / Q000502:physiology*; D053001:Tool Use Behavior
diet specialization; mitogenome; sea otter; tool