Michael ClappMichael ClappCAM Jr/Sr High ~ Battle Ground, WACAM Jr/Sr High ~ Battle Ground, WA

revised: September 2006revised: September 2006

Know Your Macros!Know Your Macros!

What are Benthic Macroinvertebrates?What are Benthic Macroinvertebrates?

Commonly referred to as: Commonly referred to as: “macros”“macros”

Benthic = bottom dwellingBenthic = bottom dwelling Macro = large enough to be seen Macro = large enough to be seen

without aid of a microscopewithout aid of a microscope Invertebrate = without a Invertebrate = without a

backbonebackbone

Why Study Macros?Why Study Macros?

Macros have different tolerances to pollutionMacros have different tolerances to pollution Some are sensitive, others are tolerant Some are sensitive, others are tolerant They’re used as bio-indicators of water They’re used as bio-indicators of water

qualityquality They live in habitat continuously over an extended They live in habitat continuously over an extended

period of timeperiod of time affected by sporadic changes (chemical leaks, …)affected by sporadic changes (chemical leaks, …) affected by seasonal variations of streamaffected by seasonal variations of stream

Macros are COOL!Macros are COOL!

Identifying MacrosIdentifying Macros Based on observable physical characteristicsBased on observable physical characteristics Organisms are identified using keys, requires …Organisms are identified using keys, requires …

awareness of distinguishing features awareness of distinguishing features knowledge of life cycle (larva, pupa, adult)knowledge of life cycle (larva, pupa, adult)

Classification of organismsClassification of organisms Different levels of classification (taxa)Different levels of classification (taxa) Levels progress from general groupings to more specificLevels progress from general groupings to more specific ID to Class & Order level (possibly Family)ID to Class & Order level (possibly Family)

Professional Scientists use scientific namesProfessional Scientists use scientific names Binomial (two names)Binomial (two names) Based on Latin/Greek languageBased on Latin/Greek language Scientific Name =Scientific Name = Genus species Genus species

E-P-T: Important Indicators SpeciesE-P-T: Important Indicators Species

Ephemeroptera - mayfliesEphemeroptera - mayflies

Plecoptera - stonefliesPlecoptera - stoneflies

Tricoptera - caddisfliesTricoptera - caddisflies

Mayflies (Order Ephemeroptera)Mayflies (Order Ephemeroptera)

Six legs attached to thoraxSix legs attached to thorax Thorax does not appear Thorax does not appear

divideddivided Gills along the abdomen Gills along the abdomen 2 or 3 tails 2 or 3 tails 1 pair wing pads, if present1 pair wing pads, if present Generally collector Generally collector

gatherers and shreddersgatherers and shredders Sensitive or moderately Sensitive or moderately

tolerant of pollution tolerant of pollution

head

thorax

abdomen

2 plates

gills

tails orcerci

Mayflies (Order Ephemeroptera)Mayflies (Order Ephemeroptera)

Common Families:Common Families: AmeletidAmeletid Small MinnowSmall Minnow Flat-headedFlat-headed Spiny CrawlerSpiny Crawler Prong-gilledProng-gilled

Stoneflies (Order Plecoptera)Stoneflies (Order Plecoptera)

Thorax divided into 3 partsThorax divided into 3 parts Pair of legs for each partPair of legs for each part 2 claws at end of each leg2 claws at end of each leg

2 pair wing pads, if present2 pair wing pads, if present Only 2 tailsOnly 2 tails Gills Gills maymay be visible on be visible on

thorax (“hairy armpits”) or thorax (“hairy armpits”) or under neckunder neck

Shredders and predatorsShredders and predators Mostly sensitive to pollutionMostly sensitive to pollution

2 tails

abdomen

thorax

head

3 plates

sometimes gills visible on thorax

2 claws

Stoneflies (Order Plecoptera)Stoneflies (Order Plecoptera)

Common Families:Common Families: GoldenGolden Little Yellow Little Yellow Little Green Little Green Little BrownLittle Brown Slender WinterSlender Winter GiantGiant

Wing pads

Caddisflies (Order Trichoptera)Caddisflies (Order Trichoptera) 6 legs attached to thorax6 legs attached to thorax Fleshy abdomen; some with hair-Fleshy abdomen; some with hair-

like gillslike gills Prolegs with hooks at end of Prolegs with hooks at end of

abdomen; some have tufts of hair abdomen; some have tufts of hair Some build cases from rocks Some build cases from rocks

and/or plant materialand/or plant material Some spin nets as a retreat and to Some spin nets as a retreat and to

collect detrituscollect detritus Some crawl around in search of Some crawl around in search of

preyprey Sensitive or moderately sensitive Sensitive or moderately sensitive

to pollutionto pollution

headthorax

abdomen

abdominal gills (Netspinner)

prolegs with hooks

Caddisflies (Order Trichoptera)Caddisflies (Order Trichoptera)

Common Families: Common Families: Northern casemaker Northern casemaker Saddle casemakersSaddle casemakers Humpless case-makerHumpless case-maker Netspinner Netspinner

(Hydropsychidae)(Hydropsychidae) Freeliving (green rock Freeliving (green rock

worm)worm) FingernetFingernet

Freeliving (predators)

Other Common Taxa Other Common Taxa of Aquatic Macrosof Aquatic Macros

Worms: flatworms, earthworms, & leechesWorms: flatworms, earthworms, & leeches Mollusks: snails, mussels, & clamsMollusks: snails, mussels, & clams Arachnids: water mitesArachnids: water mites Crustaceans: aquatic sowbugs, scuds, & Crustaceans: aquatic sowbugs, scuds, &

crayfishcrayfish Insects: true bugs, beetles, dragonflies & Insects: true bugs, beetles, dragonflies &

damselflies, dobsonflies & alderflies, midges, damselflies, dobsonflies & alderflies, midges, black flies, & crane fliesblack flies, & crane flies

FlatwormsFlatworms

Flattened body; not Flattened body; not segmentedsegmented

Eyespots (usually visible)Eyespots (usually visible) ““Glides” over surfacesGlides” over surfaces Somewhat tolerantSomewhat tolerant

Aquatic Earthworm Aquatic Earthworm (Class Oligochaeta)(Class Oligochaeta)

Round, segmented Round, segmented bodybody

Small hair-like bristles Small hair-like bristles along bodyalong body

Tolerant of pollutionTolerant of pollution

Snails (Class Gastropoda)Snails (Class Gastropoda) Hard spiral shellHard spiral shell Gilled snails (right-side Gilled snails (right-side

opening with narrow opening with narrow end up) are somewhat end up) are somewhat sensitivesensitive

Pouch snails (left-side) Pouch snails (left-side) are tolerantare tolerant

limpet

Clams & Mussels (Class Clams & Mussels (Class Bivalvia) Bivalvia)

2 shells hinged together2 shells hinged together Clams are smaller and Clams are smaller and

rounder than musselsrounder than mussels Somewhat tolerant of Somewhat tolerant of

pollutionpollution Important for stream Important for stream

health because they health because they filter feed and clean the filter feed and clean the waterwater

clam

mussel

Water Mites (Arachnids)Water Mites (Arachnids) Round body with no visible Round body with no visible

segmentssegments 8 legs8 legs 2 finger-like pedipalps project 2 finger-like pedipalps project

forward forward Small (usually 1-3 mm); look like Small (usually 1-3 mm); look like

moving dots moving dots Most are predators, piercing their Most are predators, piercing their

prey with fang-like mouth parts; prey with fang-like mouth parts; others consume plants or carrion others consume plants or carrion or feed as external parasitesor feed as external parasites

Generally tolerant to somewhat Generally tolerant to somewhat toleranttolerant

pedipalps

Sowbugs & Scuds (Crustacea)Sowbugs & Scuds (Crustacea)

Aquatic Sow bug (Order Isopoda)Aquatic Sow bug (Order Isopoda) Tan, brown, or greyish in colorTan, brown, or greyish in color 7 pair of segmented legs7 pair of segmented legs Body flattened top-to-bottomBody flattened top-to-bottom Crawls flat on bottom of trayCrawls flat on bottom of tray

Scud (Order Amphipoda)Scud (Order Amphipoda) Curved, shrimp-like bodyCurved, shrimp-like body 7 pair of segmented legs7 pair of segmented legs Flattened from side-to-sideFlattened from side-to-side Swims on its sideSwims on its side

Crayfish (Order Decapoda)Crayfish (Order Decapoda)

CrustaceansCrustaceans 5 pairs of walking legs5 pairs of walking legs Enlarged claw at end of first Enlarged claw at end of first

pair of legspair of legs Wide flipper at end of Wide flipper at end of

abdomenabdomen Somewhat tolerant of pollutionSomewhat tolerant of pollution Omnivore - mostly eats plant Omnivore - mostly eats plant

material, but also consumes material, but also consumes carrion, scrapes algae, and carrion, scrapes algae, and preys on live macrospreys on live macros

Water Beetles (Order Coleoptera)Water Beetles (Order Coleoptera) Diverse Order of insectsDiverse Order of insects Includes Riffle beetles, Includes Riffle beetles,

Predaceous beetles, Water Predaceous beetles, Water Penny, & WhirligigsPenny, & Whirligigs

Sensitive to PollutionSensitive to Pollution

Predaceous beetle

Rifflebeetle

Whirligigbeetle

larva larva

adult

adult

Dragonflies & Damselflies Dragonflies & Damselflies (Order Odonata)(Order Odonata)

DragonfliesDragonflies Large abdomen tapers to Large abdomen tapers to

point(s), but no tailpoint(s), but no tail Internal gills are not visibleInternal gills are not visible

Damselflies Damselflies Narrow abdomen ends with 3 Narrow abdomen ends with 3

paddle-like gillspaddle-like gills Dragonflies & DamselfliesDragonflies & Damselflies

PredatorsPredators Extendable, hinged jaw Extendable, hinged jaw

captures preycaptures prey Somewhat tolerantSomewhat tolerant

gills

Dobsonflies & AlderfliesDobsonflies & Alderflies(Order Megaloptera)(Order Megaloptera)

AlderfliesAlderflies Large gill filaments along Large gill filaments along

abdomenabdomen Abdomen ends with single, long, Abdomen ends with single, long,

pointed tail filamentpointed tail filament More tolerant of pollution than More tolerant of pollution than

dobsonfliesdobsonflies Dobsonflies Dobsonflies

Stout, flexible filaments, extend Stout, flexible filaments, extend from abdomenfrom abdomen

Long, somewhat flattened bodyLong, somewhat flattened body 2 prolegs at the end, with two 2 prolegs at the end, with two

claws on each prolegclaws on each proleg Sensitive to pollutionSensitive to pollution

Midges (Order Diptera)Midges (Order Diptera)

Worm-like, but with Worm-like, but with definite head and definite head and prolegs (usually)prolegs (usually)

““Twitchy” swimmersTwitchy” swimmers Pollution tolerantPollution tolerant

headprolegs

Blackflies (Order Diptera)Blackflies (Order Diptera)

Shaped like bowling pin Shaped like bowling pin Two fans on top of head Two fans on top of head

for filteringfor filtering Attaches to substrate Attaches to substrate

with ring of hookswith ring of hooks Single proleg beneath Single proleg beneath

headhead Tolerant of pollutionTolerant of pollution

proleg

Craneflies (Order Diptera)Craneflies (Order Diptera)

Long, fleshy abdomenLong, fleshy abdomen Head often withdrawn & Head often withdrawn &

concealed by thoraxconcealed by thorax Some have pairs of prolegs Some have pairs of prolegs

beneath abdomenbeneath abdomen Somewhat tolerant (other Somewhat tolerant (other

Diptera are more tolerant)Diptera are more tolerant) Some are shedders, other Some are shedders, other

predatorspredators prolegs

head

Water Boatman & Water Water Boatman & Water Striders (Order Hemiptera)Striders (Order Hemiptera)

Water StriderWater Strider ““Skates” around on top of waterSkates” around on top of water Front legs grab & beak pierces preyFront legs grab & beak pierces prey

Water BoatmanWater Boatman Oval body with wavy lines across a Oval body with wavy lines across a

dark colored backdark colored back Oar-like legsOar-like legs

Backswimmer (not shown)Backswimmer (not shown) Similar to boatman but swims upside Similar to boatman but swims upside

downdown Dark underside & light-colored backDark underside & light-colored back CAUTION -- can bite!CAUTION -- can bite!

water strider

waterboatman

Credits & ResourcesCredits & Resources PhotosPhotos

by Michael Clapp & Jr CAM by Michael Clapp & Jr CAM science studentsscience students

Websites:Websites: www.nwnature.netwww.nwnature.net Information on CAM Jr/Sr Information on CAM Jr/Sr

High School water quality High School water quality monitoring and monitoring and macroinvertebrate study can macroinvertebrate study can be found on the web: be found on the web: www.bgsd.k12.wa.us/hml/macroswww.bgsd.k12.wa.us/hml/macros

Email:Email: clapp.michael@bgsd.k12.wa.usclapp.michael@bgsd.k12.wa.us

Resources:Resources: Macroinvertebrates of the Pacific Macroinvertebrates of the Pacific

NorthwestNorthwest by Jeff Adams and Mace Vaughanby Jeff Adams and Mace Vaughan

Freshwater Macroinvertebrates Freshwater Macroinvertebrates from Streams in WA & ORfrom Streams in WA & OR by Michael R. Clappby Michael R. Clapp

Aquatic Macroinvertebrate Field Aquatic Macroinvertebrate Field Guide and Biomonitoring Reference Guide and Biomonitoring Reference Manual for the Willamette ValleyManual for the Willamette Valley by Patrick Edwardsby Patrick Edwards

Freshwater InvertebratesFreshwater Invertebrates by J. Reese Voshell, Jr.by J. Reese Voshell, Jr.

Guide to Pacific Northwest Aquatic Guide to Pacific Northwest Aquatic MacroinvertebratesMacroinvertebrates by Rick Hafele & Steve Hinton by Rick Hafele & Steve Hinton