Title: Natural History of Stream Invertebrates: Using and Making Sense of Biotic Indices, and Beyond
1Natural History of Stream Invertebrates Using
and Making Sense of Biotic Indices, and Beyond
2Natural History
- The study and description of organisms and
natural objects, especially their origins,
evolution, and interrelationships
caddisfly
sowbug
3Natural History
- Some examples related to aquatic
macroinvertebrates might include - Ecology (relationships between living organisms
and the non-living components of the environment
in which they live) - Behavior
- Functional feeding groups
4What Problems Must Macroinvertebrates Solve
Because They Live In Streams?
- Aqueous medium (tough to get O2)
- Medium that is generally moving
upstream-downstream - Diel variation in physio-chemical characteristics
- Seasonal variation in hydrology
- Connected to upstream conditions
- Linked to land-water interface
black flies
5Feeding Groups or Guilds
- Shredders - Coarse woody or plant associated
materials - Filtering Collectors - Suspended particulates,
microbes, phytoplankton - Gathering Collectors - Deposited particulates
- Grazers/Scrapers - Peryiphyton fungi
- Predators - especially invertebrates
caddisfly
stonefly
6Some Guiding Principles for Classification
- Everyone can classify objects
- Ways macroinvertebrates may be classified
- Functional feeding groups
- Morphology
- Locomotion
- Microhabitat
- Type of metamorphosis
- Means of obtaining oxygen
- Need for oxygen / Ability of stream to provide
that oxygen
net spinning caddisfly
7Biotic Indices
- A way to classify based on macroinvertebrates
tolerance to pollution - Generally this means organic pollution
- Or that which affects oxygen levels in the stream
8Biotic Indices
- Some organisms require water with a lot of oxygen
in it - Others have adaptations to obtaining the oxygen
they need
9Adaptations for Obtaining Oxygen
- Morphological
- Tubes
- Soft tissue between segments gills
- Hair-like/Plate-like wings
- Behavioral
- Body pumping
- Swimming to surface
- Construct burrows or tubes
10Biotic Indices
- Assign pollution tolerance values to organisms
based on their oxygen needs - Order level
- Fairly Simple Excellent, Good, Fair, Poor
- Tolerance values 1, 2, 3 and 4
-
- Group 1 tolerance value (4)
- Group 2 tolerance value (3)
- Group 3 tolerance value (2)
- Group 4 tolerance value (1)
- SUM A SUM B
- SUM B/SUM A Biotic Index Score
11Biotic Indices
- More tricky Excellent, Very Good, Good, Fair,
Poor, Very Poor - Weighted average Each individual is counted
(rather than just counting types) - Tolerance values 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
- If 100 organisms in sample
-
- Number of inverts in family tolerance
- 1 9 9
- 10 8 80
- 16 7 112
- 14 6 84
- 5 5 25
- 39 4 156
- 5 3 15
- 10 2 20
- 100 501
- Answer 501/100 5.01
- Gives specific types of macroinvertebrates
individual credit for being in the stream
12Diversity of Families of Aquatic Insects in
Wisconsin
- Generally find 10 Orders
- Approximately 89 Families
riffle beetle
water penny
13(No Transcript)
14What are tolerances, feeding strategies, and
presence of different families in Wisconsin
streams like?
15Mayflies use abdominal gills to obtain oxygen
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16Representative Mayflies
flathead mayfly
armored mayfly
prong gill mayfly adult
Hexagenia
17Dragonflies obtain oxygen through soft tissue
between plates Damselflies use leaf-like
abdominal gills
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18Representative Dragonflies Damselflies
broadwing damselfly larva
darner dragonfly larva
darner dragonfly adult
broadwing damselfly adult
19Stoneflies use thoracic gills to obtain oxygen
20Representative Stoneflies
common stonefly
perlodid stonefly
21True bugs may use atmospheric oxygen or may use
hair-like or tube-like modifications on their
abdomens
22Representative True Bugs
giant water bug
water strider
water scorpion
back swimmer
23Dobsonflies, fishflies, hellgrammites, and
alderflies obtain oxygen through diffusion across
soft tissue
24Spongillaflies obtain oxygen through diffusion
across soft tissue
25Representative Hellgrammites or Alderflies (Top)
Spongillaflies (Bottom)
hellgrammite
Alderfly larva
spongillafly
adult alderfly
26Caddisflies obtain oxygen through diffusion
across soft tissues and sometimes with gills and
pumping water through case
27Caddisflies obtain oxygen through diffusion
across soft tissues and sometimes with gills and
pumping water through case
28Representative Caddisflies
humpless casemaker caddisfly
saddlecase maker caddisfly
net spinning caddisfly
29Aquatic moths obtain oxygen through diffusion
across soft tissue
30Beetles obtain oxygen through diffusion across
soft tissues and from the atmosphere through
modified hairs and plate-like wings
31Representative Beetles
Riffle beetle adult
32Flies obtain oxygen through diffusion across soft
tissues including abdominal gills and atmospheric
oxygen through breathing tubes
33Flies obtain oxygen through diffusion across soft
tissues including abdominal gills and atmospheric
oxygen through breathing tubes
34Representative Flies
midge larva
cranefly larva
midge adult
35Long term sampling
36Biotic Indices arent the only solution
- Diversity indices
- Richness ( species)
- Feeding guilds
- Dont forget to think about scale
37Figure 2. Scale of Sampling and Analysis in
Streams
38- Thought Question
- What spatial and temporal scale would you choose
to sample to determine changes in populations
(number of individuals of the same species in a
given area)?