Macroinvertebrates

What is the adult form of this insect nymph?

• Earwig

• Dragonfly

• Stonefly

• Scorpionfly

In its aquatic larval stage, the caddisfly protects itself by building a protective case out of gravel, sand, twigs, and bitten-off pieces of plants. How does it bind these materials together underwater?

• With mud and silt

• By wrapping them in leaves

• Using sticky saliva

• With a silk protein excreted by specialized silk glands

All of the following are true about the stonefly except:

• Each female may produce as many as 6,000 eggs, which are dropped in masses into a stream

• The aquatic nymph does not have gills

• The nymphal stage lasts from one to four years

• The adults live several weeks

Which of the following is true about the mayfly?

• Swarms of mayflies are so dense that thy can be picked up on weather radar

• At about the same time, millions of mayfly nymphs will hatch and emerge as aquatic larvae

• Mayflies can live for several years in their aquatic adult form

• Once they emerge of water, and moult into their terrestrial adult form, mayflies only survive for one day

• All of the above

Select the factors that represent indicators of good or poor water quality in freshwater aquatic systems.

• pH

• dissolved oxygen

• nutrients like nitrogen and phosphorous

• presence or absence of particular biological organisms