MEPS 243:93-100 (2002)  -  doi:10.3354/meps243093

Genetic variability of Botryllus schlosseri invasions to the east and west coasts of the USA

Douglas S. Stoner1,2, Rachel Ben-Shlomo3,4, Baruch Rinkevich3,*, Irving L. Weissman1,5

1Hopkins Marine Station, Stanford University, Oceanview Boulevard, Pacific Grove, California 93950, USA
2Department of Biological Sciences, Program in Marine Sciences and Baruch Institute, University of South Carolina, Columbia, South Carolina 29208, USA
3Minerva Center for Marine Invertebrate Immunology and Developmental Biology, National Institute of Oceanography, Tel Shikmona, PO Box 8030, Haifa 31080, Israel
4Department of Biology, University of Haifa-Oranim, Tivon 36006, Israel
5Department of Pathology, Stanford University Medical Center, Stanford, California 94305, USA
*Corresponding author. Email:

ABSTRACT: Biological invasions are an important threat to the health and composition of coastal marine communities. One of the most important challenges for conservation biologists and ecologists is to develop methods for historically reconstructing the invasion process in order to better understand the tempo and mode of the invasion as well as to evaluate the biological consequences. Genetic markers provide 1 approach for documenting the temporal and spatial dynamics of recent invasions through characterization of the genetic structure of introduced populations. Here, we used microsatellites to determine the geographic origins of populations of the colonial ascidian Botryllus schlosseri from the east and the west coast of the USA. Specifically, we tested the hypotheses that the source of California populations was the east coast of North America. Eight populations were sampled from the east coast and California. This hypothesis was not substantiated. Rather, results suggest that either European or Asian populations are the most likely source for the introduction(s) of B. schlosseri to California.

KEY WORDS: Ascidians · Biological invasions · Heterozygote deficiency · Microsatellite · Population genetics

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