Benthic Macro-invertebrates

The Canary in the Coal Mine!

What are they?

• Benthic= Bottom Dwelling

• Macro= seen with naked eye

• Invertebrates= no back bone

Why monitor them?

• Macroinvertebrate Biodiversity Index or MBI

• Relative tolerance to pollutants called a Tolerance Value (Tv)

• A number line of 1 to 11• The lower the number

the less tolerant the species is to pollution Stone Fly = 1.5 Tv

Adaptations

• Based on their primary habitat– Riffle– Run– Pool

Flat Worm / Planaria

• Less than 2cm in length• Pointed head with two

“eye spots”• Glide along bottom of

the pan• No segments

Leeches

• 2 cm to 5cm long• Segmented• Thin head and fat tail

regions• Two movements in the

pan– Undulated swimming– Inch worm along bottom

of pan

Side by Side Comparison

Aquatic Worm

• Looks like a terrestrial worm

• Light brown in color• Segmented• Up to 10 cm long• Will crawl along bottom

of the pan

Blood Worms• Very small and thin• Up to 2cm long• Looks like a tiny red hair

in the pan• They can be found

floating and sometimes wiggling on bottom of the pan

• Get their name from color, they have nothing to do with blood

Side by Side Comparison

Caddis Flies

• Hydropshychiadae• Light colored, form a

“C” shape• Dark colored Armored

back

Caddis Fly

• Non-Hydropshychidae• GREEN with dark

colored armor plates

Get there name from”

Side by Side Comparison

Amphipoda or Scud

• AKA Freshwater shrimp• Light colored• Swim on their sides• C -Shaped

Aquatic Sow Bug/ Isopoda

• Similar to a terrestrial rolly-polly

• Light brown to grey in color

• Up to 1.5 cm long• Crawls along bottom of

pan• Does not swim

Side by Side Comaprison

Crawling Mayfly

• Three tails• Gills along abdomen• Long thin bodies• Up to 2 cm long, but

usually smaller in our creek 1cm

• Wing pads on abdomen

Clinging Mayfly

• Up to 2cm long• Colors vary• Look like they “work

out” incredible legs for clinging to rocks in fast currents

• Large eyes• 3 tails

Swimming Mayfly

• Three or two tailed. In our creek mainly 3 tailed. The two outer tails curve away and the gills are much longer and have a furry appearance

Torpedo Mayfly

• Look a little like the swimming mayfly but torpedo’s have a humped back

Burrowing Mayfly

These mayflies have a veryFurry appearance. There gillsAre all over their bodies making themLook hairy.We have found these in our creek, butHave not found them in the past several Years.

Side by Side Comparison

Meet the Mayfly!

Stone Fly• TWO TAILS ONLY• Distinctive coloration- turtle

shell markings• Very strong and hardy

looking• We do find these in our

creek but have not for two years

• Is it a mayfly or a stone fly? ASK YOUR TEACHER TO MAKE SURE! WE NEED TO DOCUMENT THIS SPECIES!

Alderfly• Reddish brown head• Lighter colored abdomen• Long gill filaments off the

side and a long single filament off rear end

• Large mandibles• Can be 1 cm to 4 cm long• LION of the creek so get it

out of your pan quick- it will eat everything else in a short amount of time!

Dobson Fly

• Large mandibles• Dark Color• Short dark gill spikes off

abdomen• OTHER LION of the

creek. Remove immediately after documenting or you will have nothing else to count! : )

Side by Side Comparison

Water Penny

• Not to be confused with an Aquatic Sow bug!

• Reminds me of a scab from the top and looks like an alien from the underside!

• Oval shaped, brown and up to 1cm long in our creek

This photo enhanced with color, naturallyWhite in color

Side by Side

Riffle Beetle

• In these case we count both the adults and larva.

• Adults will be up to 3cm in size, black and their legs look like ribbons

• The larva are light brown and with dark heads but only one armoring

Side by Side Comparison

Caddis- Hydropsychidae Riffle Beetle Larva- they sometimesCurl into a C-shape so not the armoring

Predacious Diving Beetle

• We typically only find the adult. We count the adult and the larva.

• Larva has a distinctive rounded head and these larva are big.

Broad Winged Damsel Fly

• Gills located at the tail, three large feathering looking appendages

• Can be 3 cm long

Narrow Winged Damsel Fly

• These guys typically look scary to students

• Longer pointed antennae, very long legs

• Long feathery gills on tail as well

Side by Side Comparison

Damsel Flys

Damsel Fly vs Fish

Black Fly

• Black in color with grey shading

• Rounded shape at both ends with a thin “waist”

• Typically very numerous• They are small, about 1

cm at most

Midge Fly

• Midge larva are going to be very small less them 1 cm in lenth.

• They come in a variety of colors and shapes

• They are feathery looking butts. These are their gills

Mosquito

• Very small larva that have a distinctive wiggle movement

• We do not count these in our data but they are common and can be confused for midges

Side by Side

Crane Fly

Not a worm, but does look A little like a fat caterpillar

Greenish in color

Varies from 2cm to 6cm long

Typically very big this time of year,They are responsible for shredding All of the leaves that fall in the creek

Search leaf packs for them

Snipe Fly

• Also look like a caterpillar BUT they have suction cup feet

• Usually a reddish brown color

• Also can have feathery antennae

Side by Side

Dragon Fly

• Dragon Flies come in all different shapes, sizes and colors

• We have pulled dragon fly larva out of the creek so be one the look out, but not that man over the past decade

AWESOME Drgaonflies

Left Handed Snail

• These are Lung Breathers and are more tolerant to pollution

Right Handed Snail

• These are gill breathers and are not as tolerant to pollution

Side by Side

Crayfish

• Yes, they are fun, but they do not determine water quality and we do not count them

• So, let them go please!• IF YOU FIND ONE THAT

HAS RED PATCHES ON THE BODY, please show it your teacher. It may be invasive

Fish

• We do not count fish and for their safety do not want you to keep them in your pan.

• If you do find a fish do show it to your teacher so that we can determine if it is one of the following fish

Johnny Darter- common

Sculpin- some species are Endangered

Rainbow Darter- Endangered

Round Goby- Invasive

The wonderful World of Macros!

A closer look!