Water Quality Science Olympiad Organism ID

Mayfly larva

Incomplete metamorphosis - larval development 3 mo- 3 years

Nymphs 3 tail filaments - occasionally 2 tail filaments - never paddle or fan-like

Feathery gills line the sides of the abdomen on nymph

Color of nymph- green brown, gray but usually black

Nymphs are flattened to reduce the force of fast currents

Nymphs are collector-gathers or scrapers - small plant and animal debris as algae, diatoms & plankton- they are found on underside of rocks

Nymphs are a high proportion of the diet of many fish

Class 1 pollution sensitive

Mayfly adult

Adults do not eat

Females deposit eggs on top of water where they drift to bottom - some deposit eggs under water on submerged objects

Class 1 pollution sensitive

Caddisfly larva

Complete metamorphosis

Larvae are usually cylindrical and "C" shaped

Some larvae are free-living (collector-filterers)

The larvae are found beneath stones or rocks

Some spin webs to trap food from the flowing water

Others are case makers (shedders-detritivores & shedders-herbivores)

Larvae transform into winged adults in the wate

Class 1 pollution sensitive

Caddisfly adult

Adults, they live only a few days and do not eat

One generation per year

Class 1 pollution sensitive

Stonefly larva

Incomplete metamorphosis

Eggs are laid in the water or are placed in cracks near the water's edge.

Nymphs hatch in early spring. Have two tails & no gills visible on the abdomen - also 2 tarsal claws

Nymphs usually live beneath stones in fast-moving, clean water.

They feed on algae, lichens, and rotting vegetation.

Some are predators

As they grow the nymphs molt (often more than a dozen times.

Some take a year to become adults, some take two years.

Class 1 pollution sensitive

Stonefly adult

Adults emerge near the edge of the stream, sometimes when the ice has just melted.

Most appear to emerge at night.

After emerging, the adults fly.

They are not active fliers, usually remain near the ground.

Many adult stoneflies do not have functional mouth, so they cannot eat and they live only a short time (about 2 to 3 weeks).

Adult stoneflies are found near the streams and rivers from which they emerged.

Class 1 pollution sensitive

Dobsonfly larva

Complete metamorphosis

Includes some of the largest larvae

Larvae are most often found in clean rivers with rocky bottoms - near soft rotting logs or stumps

Larvae are carnivorous predators and may bite - mouth has large chewing pinchers

Larvae have 3 pr. of well-developed legs on the thorax

Larva has many fleshy, filamentous lateral appendages on each side of the abdomen

Gill tufts on the underside of the tail of larvae

Abdomen of larvae ends in a pair of short spiny prologs each with 2 hooks

Class 1 pollution sensitive

Dobsonfly adult

Adult live only about 7 days

Class 1 pollution sensitive

Gilled snail larva

Rely on oxygen in the water for respiration

Have gills for breathing

Class 1 pollution sensitive

Gilled snail adult

Shell is made of calcium carbonate

Soft body inside a hard, spiral shaped shell

Plate-like door (called the operculum) protects the opening of the shell

Shells usually open on the right side

They are grazers found on a variety of substrates

Class 1 pollution sensitive

Water Penny (beetle larva)

Complete metamorphosis

The water penny is the aquatic larva of a beetle The body is often stuck flat to surfaces as rocks and other flat substrates and looks like a tiny round leaf

Larva is green, brown, black, or tan

Segmented plate-like covering on larva

Six tiny segmented legs beneath the round body

Larva eat plant debris as algae and diatoms

The adult of the species is not aquatic but found above water on rocks in riffles -resembles extremely large riffle beetle

Class 1 pollution sensitive

Riffle Beetle Stonefly larva

Complete metamorphosis

Larvae body is long, stiff, and segmented (up to ¾ ")

Larvae resemble small "torpedoes"

Six segmented legs on upper middle section of larvae

Back end of larva has two tiny hooks and short hairs

Class 1 pollution sensitive

Riffle Beetle Stonefly adult

Adults have small oval body only about ¼" long

Adult are aquatic and walks very slowly under water on the bottom

Adults have only one pair of antennae

Adults found more often than larva - live longer in water

Eat primarily plant material such as algae and diatoms

Class 1 pollution sensitive

Water Scorpion

Incomplete metamorphosis

Resemble elongated sticks with slender elongated bodies and long breathing tubes to take in oxygen from air as they move on surface of water

Not good swimmers - move very slowly

They hang head down from twigs and weeds

Aquatic predators - grab the prey, hold it with their front legs and seem to suck the juices out of the victim, until its body is limp and shriveled.

Adult is also aquatic predator

Class 1 pollution sensitive

Aquatic sowbug

Crustacean and isopod

Can be found on substrates or overhanging vegetation tend to crawl along surface

Omnivorous

Have 7 pr. of legs, 2 pr. antennae - one much longer than the other

Similar in appearance to terrestrial sowbugs or "roly-polys"

Class 2 moderately sensitive

Damselfly nymph

Incomplete metamorphosis

Nymphs have slender bodies with 3 long tail-like gills

Nymphs have no abdominal gills and tail supplemental gills are paddle-shaped

Long legs are close to the head

Large compound eyes and extendable jaws fold under the head - very good vision

Nymphs are grey, grey or brown in color

Nymphs found among stones and in leaf litter at bottom

Nymphs are predators and feed on other macroinvertebrates in the water - may also be cannibals eating each other

Nymphs have 10 to 12 stages of development to become adults

Class 2 moderately sensitive

Damselfly adult

Adults have long abdomens, 2 pr. wings held upright, and are very colorful - reds, greens and blues

Wings are held vertical when at rest

Adults use their hind legs covered with hairs to capture prey as they fly and devour the prey by chewing it - they live near the water

Class 2 moderately sensitive

Dragonfly nymph

Incomplete metamorphosis

Most nymphs have oval and flattened robust, elongated bodies or spider-like bodies -

Nymphs are usually grey, brown or green

Often have algae growing on their backs

No external gills on the nymph

Nymphs have large eyes, are predators with distinct mouthparts used to capture prey

Feed on aquatic macroinvertebrates, small fish and tadpoles

Class 2 moderately sensitive

Dragonfly adult

6 legs and a pair of small wings may be seen developing on the back

Three anal structures (often appear as one)

Adults similar to adult damselflies but the 2 pr. of wings are flat or horizontal when at rest rather than vertical as the damselflies

Adults are agile predators eating mainly other insects-eating food equal to its own weight in 30 minute

Class 2 moderately sensitive

Scud

Are tiny Crustacean Amphipods

Sometimes called freshwater shrimp

Are laterally compressed - side swimmers

Have 2 pr. antennae and 7 pr. of legs

Found in shallow water near overhanging vegetation

Stay close to bottom - use it to hide from predators

Predators include tadpoles, aquatic insects, small fish

Do not like light and are active at night

Filtering collector scavengers - eat dead plant and animal matter

Help keep water clean by eating dead decaying material

Primary food source for many varieties of fish including trout

After mating, eggs are held by the female in a sac until they hatch

Class 2 moderately sensitive

Crane Fly larva

Complete metamorphosis

Larvae are worm-like with thick skinned segmented body - somewhat transparent with digestive tract visible- may be greenish or grayish

Larvae are rounded at one end and disc like spiracles at the other end

Larvae are shredders - eat plants and plant debris some are predators

Class 2 moderately sensitive

Crane Fly adult

Adults nicknamed giant mosquitoes with long legs

but are do not bite humans

Adults normally do not eat and live only long enough to mate - are food for birds, spiders and some carnivorous plants

Females deposit eggs on submerged vegetation and other debris

Class 2 moderately sensitive

Water Mite

Small Arachnids

Have a complex life cycle - egg, larva, nymph and adult

Female attaches fertilized eggs to submerged plants

Larvae hatch with only 6 legs

Larva are usually parasitic on aquatic insects

Nymphs called deutonymph resemble adults with 8 legs but are sexually immature

Deutonymphs feed on aquatic insects, crustaceans, and other mites, and grows in size as it feeds

Adults- round or globular with 8 legs.

Bright red is common, but can be green, blue, orange, yellow, brown or black.

Found in shallow water (1-2 meters beneath the water surface)

Adults - mostly piercer-predators preying on insect and fish eggs, insect larva, dead organisms and bivalves

Water Mites are food for a wide variety of aquatic invertebrates

Class 3 moderatley tolerant

Blackfly

Complete metamorphosis (true fly)

Eggs are deposited in shallow, fast-running water on suspended objects as rocks,leaves, or vegetation

Larvae have brush-like mouthpart that collect tiny organisms or organic matter like a sieve out of water - collectors/filterers

Larvae tend to stay attached to substrate by producing a silk thread to adhere- tiny hooks on the abdomen help to attach

Pupa usually found on downstream side of rocks or aquatic vegetation where current is slower

Adults emerge at the same time in large numbers

Adults - many females require a special diet for egg maturation

Adult females are blood-feeders and can be very aggressive - not all adults feed on human targets - most prefer other hosts

Adult females can also transmit blood and skin parasites between mammals

Class 3 moderatley tolerant

Flatworm

Body is soft, elongate, and flattened from top to bottom

Two eyes are on the top of the head, looking

cross-eyed.

Flatworms do not undergo any metamorphosis as

they grow and develop into adults

Variety of ways of obtaining food, including piercer-predators, engulfer-predators, and collector-gatherers

They are clingers, gliding slowly planaria

Class 3 moderatley tolerant

Midge Larva

Complete Metamorphosis

Eggs laid in a mass on surface of water in a gelatinous substance

After hatching, larvae feed on gelatinous mass and then leave mass

Larvae are cylindrical, thin, soft, and often curled with anterior and posterior prologs and hardened head capsule

Larvae burrow in the mud and use salivary secretions to bind substrate particles into tubes or tunnels in which they live

Larvae feed on suspended matter in water and organic matter in the mud - gathering collector

After the first molt, most midges take on a pink color then turn into a deep red "called blood-midges or blood worms"

in low oxygen conditions (See blood midge under class 4- pollution tolerant)

Larva turn into pupa and remain for about 3 days

Class 3 moderately tolerant

Midge Adult

Adults usually swarm at night to mate and do not feed. They live only 3-5 days.

Adults sometimes nicknamed "Blind Mosquitoes" but they do not bite

Class 3 moderately tolerant

Leeches

Annelids

Segmented, flattened and a sucker on both ends of the body

Tan to brown in color

Found in areas high in organic debris or mud in shallow, still water (ponds)

Active at night

Can be carnivores, detritivores, but mostly external parasites

Free-living detritovores hid under stones or other objects and eat decomposing organic matter

Predatory leeches eat frequently

Parasitic species feed on host sucking blood from the host - releasing an anesthetic

Class 3 moderatley tolerant

Air Breathing Snail

Left opening with no plate-like covering (operculum) over opening

Respire via lungs so they are not dependent on dissolved oxygen in the water

Found grazing on a variety of substrates

Grazers

Class 4 pollution tolerant

Deer or Horse Fly

Complete metamorphosis (true fly)

Larva are caterpillar-like and segmented

Larva body is tapered on both ends with no appendages

Usually milky, light brown or greenish with digestive tract often visible

Larvae are predators, collectors and can be cannibalistic - usually eat small organisms as aquatic insects and other small invertebrates

Larva found under rocks, overhanging vegetation, or in leaf-pack

Adults emerge from pupa state, are good fliers, and immediately start mating with males and females feeding on nectar

Females feed on blood and develop eggs

Most species have only one generation per year

Class 4 pollution tolerant

Tubifex worms

aquatic annelids

slender segmented worms - resemble slender earthworms

color can be reddish, brown or gray

often found in clumps in large numbers indicate poor water quality

found in mud bottoms

eat large quantities of mud and filter organic matter from it

serve as food for fish and other bottom feeders

reproduce similar to earthworms - hermaphroditic and a cocoon serves during fertilization and development of embryos

Class 4 pollution tolerant

Blood Midge

Complete metamorphosis

Larva of the Midge (see midge above in Class 3)

Midge Larva turn blood red under low oxygen conditions

Contain substance≈to Hgb which holds O2 absorbed through gills at base of body

Eat dead plant and animal matter (detritus)

Serve as food for fish, water mites and insect larvae

Class 4 pollution tolerant

Whirligig Beetle

Complete metamorphosis -see similar life cycle under predacious diving beetle

Larvae stay at the bottom and feed on microbes and plant matter

Adults normally live on the surface of a "gentle" ponds or lakes

Adults have short antennae and forelegs that are very long and mid and hind legs that are short and paddle-like

Adults are oval-shaped and dark with a metallic sheen

Adults are capable of trapping air bubbles so that they can submerge.

Adults prey on insects and other creatures that fall on the water surface.

Common name for adults comes from their habit of swimming rapidly in circles when alarmed.

Divided eyes in adults allow them to can see both above and below water

The adults are often found in groups to avoid predators Mosquito

Class 5 Air Breathing

Water Strider

Incomplete metamorphosis (True bug) - see bug life cycle under Giant Water Bug

Known to skate on the water surface (special adaptations that enable them to remain suspended on the surface film)

Breathe from the atmosphere (when they occasionally dive or submerged, they trap air in the fine, water resistant hairs that cover their bodies

Short, raptorial front legs to grasp their prey on the water surface (piercer-predator)

A predator on other insects

The front pair of legs is adapted for grasping prey

Class 5 Air Breathing

Mosquito

Complete metamorphosis

Most lay eggs on H20 surface of water as egg raft but some species eggs are single

Prefer water sheltered from wind

Most eggs hatch within 48 hours

Larvae are nicknamed "wigglers" or "wrigglers"

Larvae stay near the water surface for feeding and breathing (collector-filterers or collector-gatherers)

Larvae have siphon tubes for breathing and hang from the surface of the water

Larvae feed on micro-organisms and organic matter in the water

Mosquito larvae can live in almost every type of still-water habitat

On the 4th molt the larva turns into a pupa

Pupal stage is a resting, non-feeding stage where the adult develops

Pupa takes in oxygen through two breathing tubes "trumpets"

Male mosquitoes feed only on plant juices

Only female mosquitoes bite other animals using blood to allow her to develop eggs

Female looks for movement of dark objects

Female inserts its proboscis and probes for blood vessels where it injects saliva into the wound

The saliva has anticoagulant but may contain pathogens - malaria parasites ,encephalitis viruses

Class 5 Air Breathing

Giant Water Bug

Incomplete metamorphosis (True Bug)

Female deposit their eggs on the backs of males, which carry them until they hatch (common with other surface swimming water bugs as water boatman, backswimmer, and water strider)

Mostly inhabit ponds, edges of lakes, and pools of streams

Nymphs of water bugs molt several times before reaching adult

Nymphs receive oxygen through their skin in pockets at the tip of the abdomen

Adults breath air from the surface of the water (common with other surface swimming water bugs as water strider, backswimmer, and water boatman)

Adults will inflict a painful bite with their beak

Nymphs and adults are fierce predators - inject chemicals that kill prey and dissolve internal parts of prey - feeding on tadpoles, small fish, salamanders and small frogs

Front legs are greatly widened and elbowed for grabbing and holding prey. (piercer-predators)

May be up to 3 inches long

Class 5 Air Breathing

Back Swimmer

Incomplete metamorphosis (True Bug) - see bug life cycle under Giant Water Bug

Swims on its back paddling with long fringed hind legs

Back is convex with wings white or lightly colored with cross striations - can have green, brown or yellowish color (wings are lighter than the body area)

Nymphs of water bugs molt several times before reaching adult

Nymphs receive oxygen through their skin in pockets at the tip of the abdomen

Adults breath air from the surface of the water

Nymphs and adults are predators and attack prey as aquatic insects up to large as tadpoles and small fish

Can inflict painful bite even to humans

Adults are also good fliers with well developed wings - attracted to lights and may invade home swimming pools

Class 5 Air Breathing

Water Boatman

Incomplete metamorphosis (True Bug)

-Adult swims upright - back is dark

Grayish, elongated oval body with large eyes

Paddle along surface of water with oar-like back legs

Nymphs of water boatman molt five times before reaching adult

Nymphs receive oxygen through their skin in pockets at the tip of the abdomen

Adults breath air from the surface of the water

Can carry air bubble on body surface or under wings while they are under water

Most are herbivorous - living on algae and plant matter

They live in clusters or groups - adults can fly

Unlike other aquatic buds, they do not bite humans

Class 5 Air BreathingP

Predacious Diving Beetle

Complete metamorphosis

Live in ponds, lakes and slow-moving streams

Larvae are predators

Adults are black or brown; some with markings

Adults come to water surface to get oxygen from air

Eat tadpoles and small fish

Are food for fish, frogs, water spiders

Class 5 Air Breathing

Purple Loosestrife

Aquatic Nuisance Plants

Eurasian Water Milfoil

Aquatic Nuisance Plants

Water Hyacinth

Aquatic Nuisance Plants

Zebra Mussel

Aquatic Nuisance Animals

Spiny Water Flea

Aquatic Nuisance Animals

Asian Tiger Mosquito

Aquatic Nuisance Animals

Carp

Aquatic Nuisance Animals