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The population of native white-clawed crayfish in English rivers is decreasing due to an increasing population of American imported signal crayfish - Edexcel - GCSE Biology - Question 1 - 2021 - Paper 1
Question 1
The population of native white-clawed crayfish in English rivers is decreasing due to an increasing population of American imported signal crayfish. Figure 1 shows ... show full transcript
Worked Solution & Example Answer:The population of native white-clawed crayfish in English rivers is decreasing due to an increasing population of American imported signal crayfish - Edexcel - GCSE Biology - Question 1 - 2021 - Paper 1
Step 1
Which term is used to describe the American imported signal crayfish now that it is living in English rivers?
Answer
The correct term to describe the American imported signal crayfish in English rivers is B) non-indigenous species. This term is used because this species is not originally from this region and has been introduced, likely leading to ecological impacts.
Step 2
Explain one other reason why the increasing population of American imported signal crayfish may have caused the decrease in white-clawed crayfish.
Answer
Another reason the increasing population of American imported signal crayfish may lead to a decrease in white-clawed crayfish is that the American signal crayfish can outcompete native species for resources. They often have a higher reproductive rate and may dominate food sources and habitat, thereby reducing the survival and reproduction chances of the native white-clawed crayfish.