1 Citizens’ Environment Watch Water Quality Monitoring with Benthic Macroinvertebrates Benthic Macroinvertebrate Identification Guide

2 Coelenterata (Hydras) Size range: 2-25 mm long Movement: sessile Colour: variable, often clear to whitish Inconspicuous, tube with tentacles Asexual reproduction through budding

3 Turbellaria (Flatworm) Size range: 5-30 mm Movement: creep slowly on bottom Colour: greyish brown, often ‘colourless’ very flat unsegmented eyespots on head

4 Nematoda (Roundworms) Size range: usually <1 cm long Movement: Rapid, whip- like movements Colour: usually transparent Unsegmented Usually tapered at both ends

5 Oligochaeta (Aquatic Earthworm) Size range: 1-30 mm Movement: crawl along bottom of tray Colour: pinkish, light brown Similar appearance to earth worm, with bundles of hairs on each segment behind the first Segmented body with clitellum (swollen, glandular region)

6 Hirudinea (Leech) Size range: mm Movement: inch along bottom with the aid of suckers at either end of body Colour: brown, black, green on top/orange on bottom Segmented body Often with several pairs of eyes on head

7 Isopoda (Sow Bug) Size range: 5-20 mm Movement: crawl slowly on bottom Colour: brownish, red Many pairs of legs (up to 8) Dorso-ventrally compressed Often associated with organic matter

8 Pelecypoda (Clam) Size range: mm Movement: none (found at bottom of tray) Colour: white, yellow, brown, grey, black Hard shell Flat, 2 halves hinged Do not count empty shells

9 Amphipoda (Scud) Size range: 5-20 mm Movement: swim on side Colour: blueish grey, brown, green, red Many pairs of legs (up to 14) Long antennae

10 Decapodae (Crayfish) Size range: mm Movement: walk on bottom Colour: green, brown, blue Similar appearance to lobster Large claws Eyes on small stalks Escapes backwards by beating tail

11 Hydrachnida (Water Mite) Size range: mm Movement: appear like a small moving dot - uncoordinated, scrambling Colour: bright red, green, blue or brown Round body 4 pairs of legs

12 Ephemeroptera (Mayfly) Size range: 3-28 mm (not including tail) Movement: Swim up and down in ‘s’ pattern Colour: brown or brownish black (sometimes mottled) 3 pairs of legs Single tarsal claw Feather-like gills under abdomen 3 tail filaments (sometimes only 2 filaments are present)

13 Anisoptera (Dragonfly) Size range: mm Movement: slow Colour: green to greenish brown Larger than mayfly but without tail filaments; no visible external gills Modified labium for catching prey Large eyes and head Often flat

14 Zygoptera (Damselfly) Size range: mm Movement: slow moving but more active than dragonflies Colour: green to greenish brown 3 gills present on end of tail Thinner than dragonfly Three pairs of legs

15 Plecoptera (Stonefly) Size range: 5-50mm Movement: slow Colour: yellowish, brown or blackish (sometimes mottled) Similar to mayfly but with 2 tail filaments Sometimes feather- like gills under body (not dorso-lateral on abdomen) Tarsi with 2 claws

16 Hemiptera (True Bug) Size range: mm Movement: swimming or skimming on water surface Colour: black or brownish Legs sometimes long and stick out from body Often 2 pairs of soft folded wings Often with well developed breathing appendages Sucking mouth parts (rostrum)

17 Megaloptera (Helgrammite) Size range: mm Movement: Crawl on bottom Colour: brown Large, similar in appearance to centipedes (the ‘hairs’ are actually gill filaments) 3 pairs of legs in anterior abdominal segments Well developed mandibles Often with anal prolegs

18 Trichoptera (Caddisfly) Size range: 2-50 mm Movement: Slow movements on bottom Colour: abdomen cream coloured Often no movement if found in cases of sticks, stone or sand (look for heads inside cases) Three pairs of legs behind head Dorsal thoracic plates variously sclerotized Anal prolegs with hooks

19 Lepidoptera (Aquatic Moths) Size range: mm Movement: crawls like a caterpillar Head with ring of ocelli (small simple eye) 3 pairs of short, segmented, thoracic legs (between head and abdomen) Ventral, abdominal prolegs

20 Coleoptera (Beetle) Size range: 2-40 mm Movement: swimming or crawling on bottom Colour: brown, black, mottled Most have 3 pairs of legs near head Larvae are similar to caddisfly larvae but bodies are hard, with mandibles, maxillae, labium and 2- or 3-segmented antennae; may have unsegmented terminal abdominal appendages Adults: hardened forewings protect soft hind wings, antennae with 11 or fewer segments

21 Gastropoda (Snail) Size range: 2-70 mm Movement: none (found floating or at bottom of tray) Colour: grey, brown or black Hard shell Spiral shaped Do not count empty shells

22 Chironomidae (Midge) Size range: 2-20 mm Movement: whip back and forth Colour: red, white or cream Segmented body Shaped like letter “J” when preserved May be in tube of silt Well developed, hardened head with eyes; anterior and posterior parapods (lobed shaped body extensions)

23 Tabanidae (Horsefly) Size range: mm Movement: unknown Colour: white or cream pointed at both ends, leathery texture Segmented, straight or slightly curved 7 pairs of bumps on abdomen (creeping welts with hooks) Head retracted into thorax

24 Culicidae (Mosquitos) Size range: 3-15 mm Movement: twitches when touched Colour: brown Thickened body at head Segmented body, curved at one end

25 Ceratopogonidae (no-see-ums) Size range: 3-13mm Movement: whipping motion, but stiff when picked up Very slender, pointed at both ends, segmented; small pointed sclerotized (hard) head No abdominal appendages; may have some terminal abdominal hairs

26 Tipulidae (Cranefly) Size range: mm Movement: similar to a worm Colour: white, yellowish or light brown One end with finger like projection, lobes or long hairs Reduced head is retracted into thorax Soft body; may have creeping welts

27 Simuliidae (Blackfly) Size range: 3-15 mm Movement: Similar to an inch worm Colour: brown or greyish Often with labral fans Similar to flattened maggot with one end 1/3 fatter Sessile (non-motile), attached at posterior end

28 Misc. Diptera (Misc. True Flies) Size range varies May have parapods, pseudopodia (temporary projection), creeping welts or other appendages, but no jointed thoracic legs Often maggot-like; head may be retracted into thorax Adults with one pair of wings

29 References Images and characteristics adapted from Gartner Lee Limited, 1997 and Ontario Benthos Biomonitoring Network, 2005 Commonness rankings from Jacques Whitford Environmental Limited, 2001 Tolerance values taken from Watershed Report Card, 2000

30 Thank You! For more information, please contact: Citizens’ Environment Watch 401 Richmond St. W. Suite 380 Toronto ON M5V 3A8 P: (647) F: (416)