NaturalHistoryBIandB eyondforWeb2007

Natural History of Stream Invertebrates: Using and Making Sense of Biotic Indices, and Beyond: 

Natural History of Stream Invertebrates: Using and Making Sense of Biotic Indices, and Beyond

Natural History: 

Natural History The study and description of organisms and natural objects, especially their origins, evolution, and interrelationships caddisfly sowbug

Natural History: 

Natural 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

What Problems Must Macroinvertebrates Solve Because They Live In Streams?: 

What 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

Feeding Groups or Guilds: 

Feeding 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

Some Guiding Principles for Classification: 

Some 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

Biotic Indices: 

Biotic 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

Biotic Indices: 

Biotic Indices Some organisms require water with a lot of oxygen in it Others have adaptations to obtaining the oxygen they need

Adaptations for Obtaining Oxygen: 

Adaptations 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

Biotic Indices: 

Biotic 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

Biotic Indices: 

Biotic 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

Diversity of Families of Aquatic Insects in Wisconsin: 

Diversity of Families of Aquatic Insects in Wisconsin Generally find 10 Orders Approximately 89 Families riffle beetle water penny

What are tolerances, feeding strategies, and presence of different families in Wisconsin streams like?: 

What are tolerances, feeding strategies, and presence of different families in Wisconsin streams like?

Mayflies use abdominal gills to obtain oxygen: 

Mayflies use abdominal gills to obtain oxygen Page 23

Representative Mayflies: 

Representative Mayflies flathead mayfly armored mayfly prong gill mayfly adult Hexagenia

Dragonflies obtain oxygen through soft tissue between plates; Damselflies use leaf-like abdominal gills: 

Dragonflies obtain oxygen through soft tissue between plates; Damselflies use leaf-like abdominal gills Page 23

Representative Dragonflies & Damselflies: 

Representative Dragonflies & Damselflies broadwing damselfly adult darner dragonfly adult darner dragonfly larva broadwing damselfly larva

Stoneflies use thoracic gills to obtain oxygen: 

Stoneflies use thoracic gills to obtain oxygen

Representative Stoneflies: 

Representative Stoneflies common stonefly perlodid stonefly

True bugs may use atmospheric oxygen or may use hair-like or tube-like modifications on their abdomens: 

True bugs may use atmospheric oxygen or may use hair-like or tube-like modifications on their abdomens

Representative True Bugs: 

Representative True Bugs water strider water scorpion back swimmer giant water bug

Dobsonflies, fishflies, hellgrammites, and alderflies obtain oxygen through diffusion across soft tissue: 

Dobsonflies, fishflies, hellgrammites, and alderflies obtain oxygen through diffusion across soft tissue

Spongillaflies obtain oxygen through diffusion across soft tissue: 

Spongillaflies obtain oxygen through diffusion across soft tissue

Representative Hellgrammites or Alderflies (Top) & Spongillaflies (Bottom): 

Representative Hellgrammites or Alderflies (Top) & Spongillaflies (Bottom) Alderfly larva hellgrammite spongillafly adult alderfly

Caddisflies obtain oxygen through diffusion across soft tissues and sometimes with gills and pumping water through case: 

Caddisflies obtain oxygen through diffusion across soft tissues and sometimes with gills and pumping water through case

Caddisflies obtain oxygen through diffusion across soft tissues and sometimes with gills and pumping water through case: 

Caddisflies obtain oxygen through diffusion across soft tissues and sometimes with gills and pumping water through case

Representative Caddisflies: 

Representative Caddisflies net spinning caddisfly humpless casemaker caddisfly saddlecase maker caddisfly

Aquatic moths obtain oxygen through diffusion across soft tissue: 

Aquatic moths obtain oxygen through diffusion across soft tissue

Beetles obtain oxygen through diffusion across soft tissues and from the atmosphere through modified hairs and plate-like wings: 

Beetles obtain oxygen through diffusion across soft tissues and from the atmosphere through modified hairs and plate-like wings

Representative Beetles: 

Representative Beetles Riffle beetle adult

Flies obtain oxygen through diffusion across soft tissues including abdominal gills and atmospheric oxygen through breathing tubes: 

Flies obtain oxygen through diffusion across soft tissues including abdominal gills and atmospheric oxygen through breathing tubes

Flies obtain oxygen through diffusion across soft tissues including abdominal gills and atmospheric oxygen through breathing tubes: 

Flies obtain oxygen through diffusion across soft tissues including abdominal gills and atmospheric oxygen through breathing tubes

Representative Flies: 

Representative Flies midge larva cranefly larva midge adult

Long term sampling: 

Long term sampling

Biotic Indices aren’t the only solution: 

Biotic Indices aren’t the only solution Diversity indices Richness (# species) Feeding guilds Don’t forget to think about scale…

Slide37: 

Figure 2. Scale of Sampling and Analysis in Streams

Slide38: 

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)?