Reference no: EM133341822
Assignment:
Before this, read through the UCLA: invasive crayfish lead to more mosquitoes and risk of disease in Southern California and Assessing effects of non-native crayfish on mosquito survival.
1. Red swamp crayfish are a/an _______________ in California.
a) keystone species
b) introduced species
c) threatened species
d) flagship species
2. Which of the following best describes the controlled experiment conducted by the researchers?
a) The researchers removed crayfish from streams in Santa Monica and observed what happened to mosquito and dragonfly populations as a result.
b) The researchers set up tanks with only crayfish, tanks with only dragonfly nymphs, and tanks that had both.
c) The researchers sampled streams in Santa Monica and compared the number of dragonfly nymphs and mosquito larvae in streams with and without crayfish.
d) The researchers gave crayfish the choice of dragonfly nymphs or mosquito larvae to see which they preferred to eat.
3. ANSWER: According to the results of the study, __Dragonfly Nymphs__ are a more efficient predator of mosquito larvae than crayfish.
4. How do crayfish impact ecosystem services?
a) They enhance the water quality of freshwater ecosystems.
b) They reduce the biodiversity of an area.
c) They boost the primary productivity of an area.
d) They indirectly increase the prevalence of human diseases.
5. What would be the most likely effect of removing crayfish from streams in the Santa Monica Mountains?
a) Recreational use of the streams by fishermen would decrease.
b) Food webs would collapse.
c) Dragonfly nymphs would decrease in abundance.
d) Disease vectors would return to being naturally regulated.