Zebra mussels, which do not reach high densities in Europe, are a major pest in North America because they are
A) native to North America.
B) less subject to predation and pathogens in North America than in Europe.
C) not a food delicacy, as they are in Europe.
D) All of the above
E) None of the above

Question

Quizplus · Accepted Answer

Zebra mussels are less subject to predation and pathogens in North America than in Europe, which allows them to reach higher densities and become a major pest in North America. They are also not a food delicacy in North America, contributing to their status as a major pest. While they are native to Europe, this is not a factor in why they are a major pest in North America.

Zebra Mussels, Which Do Not Reach High Densities in Europe