Lab 1: Stream Ecology

Question 1

Aquatic macroinvertebrates

Answer 1

animals without a backbone that live in the water and can be seen with the naked eye

Question 2

Benthic

Answer 2

bottom-dwelling (where most stream dwelling macro invertebrates live

Question 3

Riffles

Answer 3

typically the shallower, faster-flowing areas of a stream characterized by higher levels of dissolved oxygen and substrates such as stones and gravel that often create “white water”- where most benthic macro invertebrates are concentrated

Question 4

Runs

Answer 4

fairly fast-flowing areas of a stream but a bit deeper and less turbulent

Question 5

Pools

Answer 5

Deeper holes, often have a soft silty substrate, where the water is slow moving so it contains less oxygen

Question 6

Arthropods (benthic macroinverebrate in NE Iowa streams)

Answer 6

insects

PHYLUM: arthropod: has an exoskeleton

Question 7

Mollusks (benthic macroinverebrate in NE Iowa streams)

Answer 7

clams and snails

Question 8

annelids (benthic macroinverebrate in NE Iowa streams)

Answer 8

segmented worms

Question 9

Dominant forms of macro invertebrates in freshwater streams are…

Answer 9

aquatic insects in their immature forms

Question 10

Five major groups of feeders

Answer 10

grazers/scrapers, shredders, collector-gatherers, collector-filterers, and predators

Question 11

grazers/scrapers

Answer 11

feed on algae growing on surfaces

Question 12

shredders

Answer 12

consume leaf litter and larger organic materials

Question 13

collector-gatherers

Answer 13

collect find (<1mm) organic matter from the bottom

Question 14

collector-filterers

Answer 14

collect fine (<1mm) organic matter from water

Question 15

predators

Answer 15

eat and kill other organisms

Question 16

What is the best biotic indicators for assessing overall stream health and why?

Answer 16

Macroinverebrates, especially immature aquatic insects, because they tend to use particular habitats reliably and are adapted for living in those habitats.

Question 17

What limits survival of Macroinverebrates, especially immature aquatic insects?

Answer 17

Their survival is limited by the

-availability of food
-water temp
-levels of dissolved oxygen
-stream current
-presence or absence of predators
-depth and type of substrate

Question 18

What is an early warning signs of stream degradation?

Answer 18

Benthic macroinverebrates populations changing because they change in response to the limiting factors of their survival

Question 19

What is needed for a stream bioassessment?

Answer 19

The level of diversity of organisms collected and known pollution tolerance of the organisms collected

Question 20

Who developed the “biotic index” to asses water quality by looking at where particular species were found in streams in Iowa?

Answer 20

The Iowa Department of Natural Resources (2010)

Question 21

Taxa with a score of 3 are found…

Answer 21

in streams with NO organic pollution or nutrients (e.g. manure, sewage, nitrates)

Question 22

Taxa with a score of 1 are found…

Answer 22

in highly polluted streams

Question 23

Objectives of Lab 1

Answer 23

-collect environmental data (temp and dissolved oxygen) from one of two streams
-collect the benthic macroinveretbrates from a riffle in assigned stream
-ID all types of invertebrates present in sample

Question 24

Materials used for lab 1

Answer 24

-knee boots
-D-net
-plastic wash basin

Question 25

Many of organisms collected will be….

Answer 25

immature larval or nymph stages of insects (phylum: Arthropoda, class: Insecta)

Question 26

Snails and clams are in the phylum…

Answer 26

Mollusca

Question 27

segmented worms are in the phylum…

Answer 27

Annelida

Question 28

Whats the most abundant benthic macroinvertebrate and what classifies them?

Answer 28

Insects
-3 body regions (head, thorax, abdomen) NOT 3 SEGMENTS
-one pair of antennae
-3 pairs of “true” legs attached to thorax
-may also have fleshy bumps on abdomen called ‘prolegs’
-adults have 0,1, or 2 pairs of wings