Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

Journal of Great Lakes Research
By: , and 



Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.
Publication type Article
Publication Subtype Journal Article
Title Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2010.04.012
Volume 36
Issue 3
Year Published 2010
Language English
Publisher Elsevier
Publisher location Amsterdam, Netherlands
Contributing office(s) Lake Ontario Biological Station
Description 6 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Great Lakes Research
First page 499
Last page 504
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