Mercenaria mercenaria introductions into Florida, USA, waters: duration, not size of introduction, influences genetic outcomes

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 5:49-62 (2009) - DOI: https://doi.org/10.3354/ab00137 Mercenaria mercenaria introductions into Florida, USA, waters: duration, not size of introduction, influences genetic outcomes William S. Arnold*, Stephen P. Geiger, Sarah Peters Stephenson Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 Eighth Avenue SE, St. Petersburg, Florida 33701-5020, USA *Email: bill.arnold@myfwc.com ABSTRACT: Wild stocks of hard clams from the genus Mercenaria historically supported commercial fisheries, but, as these stocks have been depleted, market demand has been filled by clams produced in aquaculture operations. Along the east coast of the USA, M. mercenaria is indigenous and used for aquaculture. Indigenous Gulf of Mexico (GOM) clam populations consist of M. campechiensis, a species less suited to aquaculture because of its short shelf life. Aquaculture operations have introduced M. mercenaria into GOM waters, resulting in altered Mercenaria species composition to the detriment of M. campechiensis. Where M. mercenaria have been introduced, the population now includes both M. mercenaria and M. campechiensis, and hybrids are common. This is particularly evident where commercial aquaculture is ongoing and introductions are, therefore, continuous. Where short-term introductions have occurred for research purposes, M. mercenaria is restricted to oyster reefs. At those sites, and at sites where no documented introductions of M. mercenaria have occurred, hybrids are rare and M. campechiensis dominate the more common sand/seagrass habitats. As the 2 species continue to interbreed, pure M. campechiensis will become rarer and hybrids more common, potentially resulting in reduced fitness of M. campechiensis from GOM waters. The trend towards hybrids may be ameliorated by an increased intensity of gonadal neoplasia in the hybrid clams. These results indicate that M. mercenaria introductions into the GOM, even on the relatively small scale of scientific research efforts, have a substantial and long-lasting influence on the genotype composition of hard clam populations in GOM waters. KEY WORDS: Aquaculture · Introduction · Hard clam · Hybrid · Introgression · Mercenaria · Population genetics · Neoplasia Full text in pdf format PreviousNextCite this article as: Arnold WS, Geiger SP, Peters Stephenson S (2009) Mercenaria mercenaria introductions into Florida, USA, waters: duration, not size of introduction, influences genetic outcomes. Aquat Biol 5:49-62. https://doi.org/10.3354/ab00137Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 5, No. 1. Online publication date: February 10, 2009 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2009 Inter-Research.