五大湖鱼类以入侵胭脂虾为食

The latest invader¹ of the Great Lakes -- Hemimysis anomala, or more commonly the bloody² red shrimp³ after its bright red spots -- may become a new food source for fish, allaying⁴ concerns about how it will impact native fish populations. "Forecasting how an invader will affect the growth and production of a specific native fish species is very relevant to conservation groups and government agencies hoping to conserve⁵ those fish," says Biology graduate student Mike Yuille.

Mr. Yuille is the lead author of a study that suggests for the first time that several native fish species have incorporated the bloody red shrimp into their diet over a multi-seasonal period.

In addition to using traditional stomach content analyses, researchers measured the carbon and nitrogen signatures of muscle tissues of three potential Hemimysis predators⁶（捕食者） (round goby虾虎鱼, yellow perch⁷黄鲈, and alewife) to get a long-term picture of eating habits. All three predators exhibited increased nitrogen or carbon signatures, suggesting they had been feeding on prey⁸ with signatures very similar to Hemimysis. The team found these signatures in sites with dense⁹ populations of bloody red shrimp.

Like zebra mussels（贻贝） , Hemimysis anomala is native to the Black Sea and Caspian Sea. It probably arrived in the Great Lakes through the ballast water（压舱水） of transoceanic ship. In 2006 it was discovered in Lake Michigan and has now been found in all of the Great Lakes except Lake Superior.

Mr. Yuille co-authored the research with Queen's associate professor Shelley Arnott, Linda Campbell, and Timothy Johnson at the Ontario Ministry¹⁰ of Natural Resources' Glenora Fisheries Station in Picton.

These findings will be published in the Journal of Great Lakes Research.