Invertebrate database (Text version)
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Alderfly larva
Alderfly larvae look like caterpillars and have gills. They are
red-brown in colour. Alderfly larvae have a single, straight
tail. The three pairs of front legs have tiny pincers. These
are up to 20 mm long.
Alderfly larvae are usually on the bottom of clear, fastflowing streams. They live in mud or under stones.
Alderfly larvae have strong jaws to grab and eat their prey
(other aquatic invertebrates). Alderfly larvae are good food
for fish. (predators, carnivores)
Alderfly adults are short-lived (a few days to a few weeks)
Alderfly larvae are sensitive to pollution (8). They are very
sensitive to low oxygen levels in water and prefer cool
water.
Insect
Mayfly nymph
Mayfly nymphs have three long tails. Nymphs have gills
along their abdomen. They have short antennae and a
claw on each leg. Mayflies are up to 15 mm long.
They are usually found in cool, freshwater streams and
lakes living on the bottom under stones or among plants.
They prefer shady spots.
Mayfly nymphs are food for fish. Most mayfly nymphs eat
plant material. (herbivores, detritivores)
Mayflies can exist as nymphs between two weeks and two
years. Adults are short-lived: from a few hours to a few
days.
Mayfly nymphs are very sensitive to pollution (10). They
are very sensitive to low oxygen levels in water, chemical
pollution and sunlight. They prefer cooler water
temperatures.
Insect
Caddisfly larva
Caddisfly larvae look at bit like caterpillars. Adults are like
small, hairy moths. They have three well-developed legs on
the first three body segments. There are hooks on the last
body segment. They can be between 1.5 to 40 mm long.
Caddisfly larvae have soft bodies which are protected by a
silky case. The hooks help them stay in the case. The case
may be made of stones or pieces of wood.
Caddisfly larvae are usually found in freshwater streams
and rivers.
Caddisfly larvae eat algae and dead and decaying plants.
Some species trap insects in silky nets; some eat other
invertebrates and eggs. (herbivores, detritivores,
carnivores, predators) Caddisflies are eaten by fish.
Caddisfly can lose their cases if they are moved from the
stream.
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Caddisfly larvae are sensitive to pollution (10). They are
very sensitive to low oxygen levels, also temperature,
chemicals and particles in water.
Insect
Stonefly nymph
Stonefly nymphs have long antennae, two thin tails and
external gills. They have three pairs of well-developed legs.
There are two claws on each leg. Stonefly nymphs are up
to 13 mm long.
Stonefly nymphs are typically found living on the bottom
under stones or among aquatic plants in cool fast flowing
streams. The water temperature must be less than 25ºC.
Stonefly nymphs mostly eat dead plants and algae
(detritivores, herbivores). Some stonefly species stalk and
eat other animals. (predators, carnivores)
Stonefly nymphs can take up to two years to develop into
adults; adults are short-lived (one week to a month)
Stonefly nymphs are very sensitive to pollution (9). They
are very sensitive to low oxygen levels in water and prefer
cold water.
Insect
Water mite
Water mites all have round bodies with four pairs of hairy
legs. They look like fat little spiders. These are very small
at 1–2.5 mm long.
Water mites swim in shallow, slow-flowing water among
plants.
Water mites mostly eat animals by piercing them and
sucking out body fluids. Some eat decaying organisms and
humus. (detritivores, carnivores)
Water mites have a moveable head attached to the body
by a hinge.
Water mites are sensitive to pollution (6). They are
sensitive to changes in their environment. They are not
found in heavily polluted and saline environments,
Arachnid
Beetle larva
Beetle larvae are segmented and shaped like a cylinder.
They have six legs. They are 2–20 mm long.
Beetle larvae are found in streams, rivers, dams and lakes.
Some crawl along the bottom; others swim.
There are many different beetle larvae. (detritivores,
herbivores, carnivores) They are a food source for
waterbirds, turtles, frogs and fish.
Beetles are the largest group of insects. Larvae breathe
through their gills and do not need to come up for air.
Adults can fly.
Beetle larvae are tolerant of pollution (6). They cannot
tolerate low oxygen levels.
Insect
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Dragonfly nymph
Dragonfly nymphs have stout bodies with wing pads. They
have six legs near the head. They are up 50 mm long.
Dragonfly nymphs live on plants and among stones or at
the bottom of still and slow-flowing water.
Dragonfly nymphs mostly eat other aquatic invertebrates
(insects, crustaceans; sometimes they eat each other.
(predators, cannibals, carnivores) They are an important
source of food for fish.
Dragonfly nymphs suck in water through the abdomen and
move it across the gills. Water is squeezed out, to help
them move. Dragonflies moult 6–15 times in the nymph
stage.
Dragonfly nymphs are tolerant of pollution (4).
Insect
Water strider
Water striders have three pairs of long legs; the first pair
are shorter than the others, the second and third pairs are
twice as long as their bodies. They are up to 12 mm long.
Water striders live on the surface of the water (ponds and
slow-moving water).
Water striders mostly eat other aquatic insects; they pierce
their prey and suck them dry. (carnivores)
Water striders have water-repellent hairs on their legs that
hold tiny air bubbles so they can skate on the surface of
water fast. Water striders breathe using a thin silky layer of
hair on their bodies that holds air. Water striders gather in
groups. They will shelter when there are strong vibrations
in the water. They have scent glands that discourage fish
from eating them.
Water striders are tolerant of pollution (4). However, they
are not likely to be found in polluted water.
Insect
Whirlygig beetle
Whirlygig beetles have oval bodies with two pairs of short,
flat legs (like oars); the two long front legs can grasp prey.
They are up to 14 mm long.
Whirlygig beetles live on the surface of the water or dive
underwater near the edge of streams and ponds.
Whirlygig beetles eat insects that fall into the water.
(scavengers, carnivores) They are a food source for
waterbirds, turtles, frogs and fish.
Whirlygig beetles can leave a polluted pond by flying long
distances. The whirlygig beetle takes a bubble of oxygen
with it when it dives under the water to breathe.
Whirlygig beetles are tolerant of pollution (4).
Insect
Whirlygig larva
Whirlygig larvae have a long segmented body with many
legs. They are up to 20 mm long.
Whirlygig larvae crawl in the sediment of streams and
ponds.
Whirlygig larvae eat mites, snails, small fish, worms with
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
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Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
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Name
What they look like
soft bodies and insect larvae. (predators, carnivores)
Larvae have well-developed mandibles for feeding.
Whirlygig larvae are tolerant of pollution (4).
Insect
Freshwater yabby
Freshwater yabbies have two front claws (legs), four sets of
walking legs and a long thick tail. Their body is covered in a
shell. They are up to 200 mm long.
Freshwater yabbies live in swamps, rivers and dams with
soft mud (for burrowing). They hide beneath rocks and
branches from predators.
Yabbies eat plants and animals. (omnivores) Yabbies are
eaten by fish and birds.
Yabbies can survive a drought by digging deep into the
mud to keep moist.
They are tolerant of pollution (4). They are sensitive to
water pollution that harms their gills. They are less active at
lower temperatures. They prefer fast-flowing water with
high levels of oxygen.
Crustacean
Backswimmer
Backswimmers have a curved back, large well-developed
eyes and long, hairy legs for swimming. They are up to 11
mm long.
Backswimmers are found in slow-flowing water. They swim
on their backs on the surface or upside down in the water.
Backswimmers can catch insects, small crustaceans,
tadpoles and small fish on the water surface, pierce them
and suck out their body juices. (carnivores)
Backswimmers carry an air bubble with them. When it is
used up they return to the surface and capture another by
doing a somersault. Adults can eat nymphs!
Backswimmers are very tolerant of pollution (2). They can
survive some pollution. Backswimmers can fly from a pond
if water pollution gets too bad.
Insect
Water treader
Water treaders have short legs and a small fat body. They
are up to 5 mm long.
Water treaders live on the surface of slow-flowing or still
water. They stay near the banks and hide among the
plants.
Water treaders eat other aquatic larvae by spearing them
and sucking out their body fluids. (predators, carnivores)
Water treaders can walk or run on the surface of water.
They have fine water-repellent hairs on their legs to help
them walk on water.
Water treaders are very tolerant of pollution (2).
Insect
Damselfly nymph
Damselfly nymphs have long, slender bodies and three
pairs of legs near the head. They have large prominent
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
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What they look like
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What they eat
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Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
eyes. They are up to 35 mm long. They have three leaf-like
gills on the end of their bodies (like a tail).
Damselfly nymphs live among plants or stones at the
bottom of ponds and still water.
Damselfly nymphs mostly eat other aquatic invertebrates
(insects, crustaceans; sometimes they eat each other.
(predators, cannibals, carnivores) They are an important
source of food for fish.
They have excellent vision; 80% of their brain works on
visual information. Damselfly nymphs swim by wriggling
sideways.
Damselfly nymphs are sensitive to pollution (6). (Range
from 4-9.) They are sensitive to habitat disturbance.
Insect
Nematode
Nematodes have long, slender bodies without legs and
segments. They are often see-through. They move like a
whip. They are up to 10 mm long.
Nematodes live on the bottom of ponds in still and slowflowing water in soft mud.
Nematodes eat bacteria, fungi and plants. They can also
be parasitic. (omnivores, parasites)
Nematodes can go to sleep when conditions are bad and
return to life when things are better. They can survive
extremes of heat and cold.
Nematodes are tolerant of pollution (3). They are tolerant to
salt and different water temperatures.
Nematode
Freshwater sandhopper
Freshwater sandhoppers look like slaters or large fleas.
Their bodies are made up of hard segments, each has a
pair of legs (seven pairs of walking legs and three pairs of
swimming legs) and two pairs of antennae. They are
between 6–20 mm long.
Freshwater sandhoppers live under vegetation and rocks.
Freshwater sandhoppers mostly eat dead plants and
animals. (omnivores)
Freshwater sandhoppers swim by flicking their tail.
Freshwater sandhoppers are tolerant of pollution (3).
Freshwater sandhoppers cannot tolerate chemical
pollution.
Amphipod
Water scorpion
Water scorpions look like scorpions. They have large
pincer-like forelegs and a breathing tube at the end of their
abdomens. Range from 7-50 mm.
Water scorpions live among water weeds or in the mud.
Water scorpions mostly eat pond animals such as aquatic
insects and crustaceans, tadpoles and small fish.
(predators, carnivores)
Water scorpions spend most of their life near the shore as
they are not good swimmers. They use their breathing tube
like a snorkel.
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
Name
What they look like
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Group of animals
Name
What they look like
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What they eat
Water scorpions are very tolerant of pollution (2). Water
scorpions can tolerate low oxygen levels by breathing at
the surface or by using their breathing tubes.
Insect
Midge larva
Midge larvae are small up to 50 mm long. Segments are
shaped like beads.
Midge larvae are found anywhere where water collects.
They swim in the water well.
Midge larvae feed on algae and detritus; others are
predators. (herbivores, detritivores, carnivores)
Midge larvae can live in a single drop of water.
Midge larvae are tolerant of pollution (3). They can tolerate
low oxygen levels by breathing at the surface.
Insect
Freshwater mussel
Freshwater mussels are from 40–150 mm across. They
have two thick shells. The muscular foot is used to burrow
into the bottom of rivers.
Freshwater mussels live on the bottom of rivers and dams.
Freshwater mussels eat microscopic plants and animals.
(omnivores)
Freshwater mussels can live for 20–30 years. Water is
drawn in through one siphon and released through another.
Freshwater mussels are tolerant of pollution (3). They
cannot live in badly polluted water.
Mollusc
Water boatman
Water boatmen are between 4-10 mm long. They have
three pairs of legs; the second and third pairs are fringed
with swimming hairs; the front pair is short and look like
scoops. They have a wide, round head with large eyes and
short antennae.
Water boatmen live among the vegetation of still and slowflowing water. They swim or float to the surface.
Some water boatmen eat insect larvae and other
invertebrates. (carnivores) Some eat plant materials
(herbivores).
Water boatmen can cling to things in the water including
fish.
Water boatmen are very tolerant of pollution (2). If
conditions get bad they leave the pond and fly to another.
Common in saline and polluted water.
Insect
Diving beetle
Diving beetles are up to 34 mm long. They are smooth and
oval shaped with hairy hind legs like paddles. They have
long, slender antennae. They have wings with a cavity for
holding air.
Diving beetles swim underwater for long periods among the
reeds in fast-flowing water.
Diving beetles eat other aquatic organisms including
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
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Pollution index
Group of animals
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What they look like
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Pollution index
Group of animals
Name
What they look like
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What they eat
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Name
What they look like
Where they live
What they eat
tadpoles, insects, snails and fish that live or fall into the
water. (carnivores) They are a food source for waterbirds,
turtles, frogs and fish.
Diving beetles store air under their wings so they can
breathe under water. They fly at dusk and are attracted to
lights.
Diving beetles are very tolerant of pollution (2). If conditions
get bad they leave the pond and fly to another.
Insect
Mosquito larva
Mosquito larvae are up to 6 mm long. They have no legs,
slender antennae and are quite hairy.
Mosquito larvae swim in still or stagnant water. hang from
the surface live just below the surface
Mosquito larvae eat microscopic organisms and dead and
decaying matter. (detritivores, omnivores)
Mosquito larvae hang upside down from the surface of
water sucking air through snorkels in their tails.
Mosquito larvae are very tolerant of pollution (1). They can
tolerate low oxygen levels as they come to the surface to
breathe.
Insect
Flatworm
Flatworms are like worms; they are flat with no segments,
legs or wings. Flatworms are up to 10 mm long.
Flatworms live in dark places, on the surface of rocks and
plants.
Flatworms eat animals and dead and decaying matter.
(detritivores, carnivores)
Flatworms can glide over surfaces using hairs to move.
Flatworms are very tolerant of pollution (2). They live where
there are lots of dead plants and animals.
Platyhelminthes
Freshwater snail
Freshwater snails have a spiral shell covering their body.
Freshwater snails live in calm places, attached to rocks
and plants.
Freshwater snails eat algae and dead and decaying matter.
(detritivores, herbivores)
Freshwater snails have a rasping tongue with layers of
teeth that scrape food into the mouth.
Freshwater snails are very tolerant of pollution (1). They
can live in areas which are rich in nutrients.
Mollusc
Non-biting midges or Bloodworms
A worm like body and small antennae. Often red in colour
and called bloodworms
Live in permanent water bodies with abundant aquatic
vegetation.
Bloodworms eat algae or dead and decaying matter.
(detritivores, herbivores); Some are carnivores that eat
worms and larvae. Bloodworms are eaten by large aquatic
Special abilities
Pollution index
Group of animals
Name
What they look like
Where they live
What they eat
Special abilities
Pollution index
Group of animals
insects and fish.
Adults are referred to as gnats.
Bloodworms are very tolerant of pollution (2).
Insect
Freshwater shrimp
See-though bodies; thin outer shell, spine sticking out of
their head; fan tail; ten jointed legs, first two pairs have
pincers on the ends; swimming legs under the tail.
Prefer slow-flowing water, close to the bank, on rocks or
plants.
They eat decomposing plants, bacteria and algae.
(detritivores, omnivores) Fish eat them.
They look like small transparent prawns.
Sensitive (3). Moderately tolerant of increased nutrients.
Crustacean