Ecological interaction between sympatric Mytilus species on the west coast of Canada investigated using PCR markers


  • This paper includes research that is part of an on-going program involving the development and application of PCR-based molecular markers for use in the study of marine mussel population dynamics and genetics. Daniel Heath is using hypervariable molecular markers to study patterns of genetic variation in natural populations at the newly created University of Northern British Columbia. Dawn Hatcher is studying Marine Science at the University of South Carolina. Jerry Hilbish is continuing the study of marine mussel evolutionary genetics at the University of South Carolina.

Faculty of Natural Resources and Environmental Studies, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada V2N 4Z9. Fax: +1–604-960-5539.


M. californianus is the dominant marine mussel species on exposed rocky shores, while M. trossulus is usually the dominant mussel species in more sheltered waters on the west coast of North America. Since these species are physically indistinguishable when small (< 10.0 mm), we developed two polymerase chain reaction (PCR) -based markers to discriminate between them. Using these markers, we identified mussels taken from an exposed coast (n= 114), a sheltered harbour (n= 80), and an upper-intertidal pool (n= 42) on the west coast of Vancouver Island, British Columbia, Canada. M. californianus were found only on the open coast. Small M. trossulus (< 20.0 mm) were common to all three sample sites, but were extremely rare at larger sizes (> 20.0 mm) on the open coast. Our results indicate that M. californianus are excluded from sheltered waters via early life factors, while M. trossulus are excluded from the open coast due to mortality later in life.