Marine Biology

, Volume 156, Issue 7, pp 1375–1387 | Cite as

Phylogeography of California and Galápagos sea lions and population structure within the California sea lion

  • Yolanda SchrammEmail author
  • S. L. Mesnick
  • J. de la Rosa
  • D. M. Palacios
  • M. S. Lowry
  • D. Aurioles-Gamboa
  • H. M. Snell
  • S. Escorza-Treviño
Original Paper


We investigate the phylogeography of California (Zalophus californianus) and Galápagos (Z. wollebaeki) sea lions and describe within-population structure for the California sea lion based on mitochondrial DNA. Fifty control-region haplotypes were found, 41 from Z. californianus and 9 from Z. wollebaeki, with three fixed differences between the two species. Ranked population boundaries along the range of Z. californianus were defined based on the Monmonier Maximum Difference Algorithm, resulting in five genetically distinct populations, two in the Pacific Ocean and three inside the Gulf of California. A Minimum Spanning Network showed a strong phylogeographic signal with two well-defined clusters, Z. californianus and Z. wollebaeki, separated by six base-pair differences, supporting the existence of two genetically distinct species with an estimated divergence time of ~0.8 Ma. Results are discussed in the context of the historical geologic and paleoceanographic events of the last 1 Ma in the eastern Pacific.


Leptospirosis Pacific Population Pacific Temperate Minimum Span Network Tooth Erosion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Tissue samples were collected in México under permit No. DOO750.8106-97 from the Instituto Nacional de Ecología; in California under permit No. 1026 from the US Department of Commerce; and in Galápagos, Ecuador, under permit No. PC-009-99 from the Galápagos National Park (and permit No. 017-00 for sample export). Additional sea lion samples from San Miguel Island were kindly provided by S. Melin (US National Marine Fisheries Service) and from Galápagos by S.K. Salazar (Charles Darwin Research Station). Work in México was facilitated by A. Zavala and O. Maravilla and carried out on Mexican Navy ships. G. Heckel, L. Inclán and M.L. Anoge participated during the cruise. We acknowledge the invaluable logistical support provided by the Charles Darwin Research Station in Galápagos (through P. Robayo). Thanks to the welcome provided by A. Dizon and staff at the SWFSC Marine Mammal Genetics Laboratory and to C. Le Duc, K. Robertson and J. Hyde for their assistance in the lab. Y.S. had grants from the Mexican National Science Foundation (CONACyT), Alstom Power (Rosarito, México), and the Universidad Autónoma de Baja California. D.M.P. was supported by award No. N00014-05-1-0045 from the US Office of Naval Research, National Oceanographic Partnership Program. Supplemental funding for Galápagos sample export was provided by the Protected Resources Division of the SWFSC (through R.L. Brownell Jr.). Earlier drafts of the manuscript benefited from comments by G. Heckel. We thank to two anonymous reviewers for their valuable suggestions and comments. The experiments comply with the current laws of the USA, México and Ecuador.


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Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Yolanda Schramm
    • 1
    Email author
  • S. L. Mesnick
    • 2
  • J. de la Rosa
    • 1
  • D. M. Palacios
    • 3
    • 4
  • M. S. Lowry
    • 2
  • D. Aurioles-Gamboa
    • 5
  • H. M. Snell
    • 6
    • 7
  • S. Escorza-Treviño
    • 8
  1. 1.Facultad de Ciencias MarinasUniversidad Autónoma de Baja CaliforniaEnsenadaMexico
  2. 2.Protected Resources Division, Southwest Fisheries Science CenterNOAA FisheriesLa JollaUSA
  3. 3.Joint Institute for Marine and Atmospheric ResearchUniversity of HawaiiHonoluluUSA
  4. 4.Environmental Research Division, Southwest Fisheries Science CenterNOAA FisheriesPacific GroveUSA
  5. 5.Centro Interdisciplinario de Ciencias MarinasInstituto Politécnico Nacional. Ave. IPN s/nLa PazMexico
  6. 6.Charles Darwin Research StationCharles Darwin FoundationGalápagosEcuador
  7. 7.Museum of Southwestern Biology, Department of BiologyUniversity of New MéxicoAlbuquerqueUSA
  8. 8.Department of Biological SciencesCalifornia State University Los AngelesLos AngelesUSA

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