Ecology of Macroinvertebrates

What Problems Must Macroinvertebrates Solve Because They Live In Streams? Aqueous medium (tough to get O2) Medium that is generally moving upstream-downstream Daily variation in physio-chemical characteristics Seasonal variation in hydrology Connected to upstream conditions Linked to land-water interface black flies

Some Guiding Principles for Classification Everyone can classify objects Ways macroinvertebrates may be classified: Functional feeding groups Morphology Locomotion Microhabitat (i.e. niche) Type of metamorphosis Means of obtaining oxygen Need for oxygen / Ability of stream to provide that oxygen net spinning caddisfly

Feeding Groups

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

Ability of water to hold 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

Presence of Gills

Air bubbles

Air tube

Hemoglobulin

Plastron trapped air space next to insect’s body creates a bubble Oxygen in air space used up by insect but replaced by oxygen diffusing in from surrounding water Thus, insect never has to surface to replenish air bubble

Representative Mayflies armored mayfly flathead mayfly Adult is Leptophlebia nebulosa from http://images.google.com/imgres?imgurl=http://www.usask.ca/biology/skabugs/Ephem/mayflylarva.JPG&imgrefurl=http://www.usask.ca/biology/skabugs/Ephem/mayfly.html&h=1406&w=1663&sz=59&tbnid=iROQ4su0WhwJ:&tbnh=126&tbnw=150&hl=en&start=10&prev=/images%3Fq%3Dheptageniidae%26svnum%3D10%26hl%3Den%26lr%3D Hexagenia by Sczcytko at this website: www.uwsp.edu/water/biomonitoring/index3.htm Hexagenia prong gill mayfly adult

Body shape (Mayfly) Mayfly example of typical insect body: head, thorax, abdomen Student Watershed Research Project (SWRP) Macroinvertebrates

Mayfly adult

Representative Dragonflies & Damselflies broadwing damselfly larva darner dragonfly larva Calopteryx from www.lesinsectesduquebec.com/insecta/7-odonata... Aeshnidae? From http://www.osu.cz/katedry/kbe/grant/dolny/skeny/Odonata/Anizoptera/Aeshnidae/Anaciaeschna/Anaciaeshna_isosceles/Male/Anaciaeshna_isosceles_m-tv.jpg Aeshnidae larva from: http://images.google.com/imgres?imgurl=http://www.usask.ca/biology/skabugs/Candlelakebugs/Odonates/AeshnaL.JPG&imgrefurl=http://www.usask.ca/biology/skabugs/Candlelakebugs/CLdragon.html&h=1160&w=1663&sz=141&tbnid=Z6R7BFKFQRoJ:&tbnh=104&tbnw=150&hl=en&start=56&prev=/images%3Fq%3Daeshnidae%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN Calopterigidae larva from: http://images.google.com/imgres?imgurl=http://www.libellen.org/epallage/pictures/pubs/8calosplecretlarv.jpg&imgrefurl=http://www.libellen.org/epallage/pubs/cretacalopteryx.html&h=443&w=567&sz=19&tbnid=u6m7eEafaSwJ:&tbnh=102&tbnw=131&hl=en&start=24&prev=/images%3Fq%3Dcalopteryx%2B%26start%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN darner dragonfly adult broadwing damselfly adult

Representative Stoneflies perlodid stonefly common stonefly Isoperla from Sczcytko’s collection Common stonefly adult from: http://paaquaticfliesrus.bd.psu.edu/webroot/images/perlesta_placida.gif Perlodidae from: http://www.waterbugkey.vcsu.edu/image_uploads/perlodidae-body_kgr3_55.jpg Perlodidae adult from: http://zooex.baikal.ru/pictures/amphybiont/Perlodidae_small.jpg

Stonefly adult (Little Yellow Stone) Little Yellow Stone (Family Perlodidae, Genus Isoperla). Nymph is a predator which is sensitive to temperature and sediment pollution. Student Watershed Research Project (SWRP) Macroinvertebrates

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

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

Caddisflies (Tricoptera) Sensitive Larvae: Soft “worm-like”bodies Head contains a hard covering Larvae are known for their construction of hollow cases that they either carry with them or attach to rocks built from twigs or bark, small stones, or rolled leaves used for protection and pupation Anal hooks usually present Large - Length up to 2 inches The name Trichoptera, derived from the Greek words "trichos" meaning hair and "ptera" meaning wings, refers to the long, silky hairs that cover most of the body and wings. Student Watershed Research Project (SWRP) Macroinvertebrates

Legs and prolegs (Caddisfly) Jointed legs are used primarily for movement. Prolegs are non-jointed appendages – aren’t easily identified as legs Prolegs on midge Caddis removed from case Student Watershed Research Project (SWRP) Macroinvertebrates

Case (Caddis fly) Case 1: Fall caddis (Family Limnephilidae, Genus Dicosmoecus) Case 2: American Grannom (Family Brachycentridae, Genus Brachycentrus) Case 3: Periwinkle, Cinnamon Sedge (Family Limnephilidae, 35+ genus in Oregon) Student Watershed Research Project (SWRP) Macroinvertebrates

Caddisfly larvae w/ case October caddis Fall caddis (Family Limnephilidae, Genus Dicosmoecus) Student Watershed Research Project (SWRP) Macroinvertebrates

Representative Caddisflies humpless casemaker caddisfly saddlecase maker caddisfly Glossosomatidae from http://www.csuchico.edu/~sacperch/FRI/images/glossosomidae3_case_adj.jpg net spinning caddisfly

Aquatic moths obtain oxygen through diffusion across soft tissue Family Tolerance Feeding Guild Pyralidae Moderate Shredder

Representative Beetles Riffle beetle adult

Water Pennies (Coleoptera) Sensitive Circular-shaped Attach firmly to rocks Sensitive – need high oxygen and fast flowing water The name Coleoptera, derived from the Greek words "koleos" meaning sheath and "ptera" meaning wings, refers to the modified front wings which serve as protective covers for the membranous hind wings. Student Watershed Research Project (SWRP) Macroinvertebrates

Representative Flies midge larva cranefly larva midge adult Cranefly from http://www.cals.ncsu.edu/course/ent525/water/aquatic/images/19.jpg Chrinomidae adult from http://www.csuchico.edu/~sacperch/FRI/images/E-chironomid_adult_adj.jpg cranefly larva midge adult

Cranefly (Diptera) Wide Range Worm-like Head capsule, usually retracted into “accordion-like” body Shredders The name Diptera, derived from the Greek words "di" meaning two and "ptera" meaning wings, refers to the fact that true flies have only a single pair of wings. Student Watershed Research Project (SWRP) Macroinvertebrates

Midge Larvae (Diptera) Tolerant Pear-shaped body, with swollen base where they attach Filter feeders                                                                                               

Crayfish (Decapoda) Wide Range 4 pairs of walking legs Large pair of pinchers Up to 6 inches Deca = ten, poda = legs Student Watershed Research Project (SWRP) Macroinvertebrates

Scuds (Amphipoda) Wide Range “Shrimp-like” Prefer muddy substrate with rooted vegetation amphi = both (as in both sides, all around), poda = feet Student Watershed Research Project (SWRP) Macroinvertebrates

Snails (Gastropoda) Tolerant Cylindrical shell May be right or left handed Gastro = stomach, poda = foot Student Watershed Research Project (SWRP) Macroinvertebrates