Water Snail Damselfly - La Trobe University

Water Snail
Class Gastropoda
Water snails are molluscs. They have small
horny teeth that they use to feed on water
plants and algae by scaping it off hard
surfaces such as rocks and logs. They have a
coiled shell and grow up to 2 centimetres in
length. These snails breathe air and fill their
lungs with oxygen when they come to the
surface of the water. They lay their jelly-like
eggs in groups on rocks or the leaves of water
plants.
Water snails are hermaphrodites. That
means that they are neither boys or girls
and can fertilise their own eggs!
Damselfly
Order Odonta
Suborder Zygoptera
Damselflies look similar to dragonflies except
they are smaller and have more slender
bodies. Their larvae are aquatic and have
three gills at the end of their bodies that look
like tails. Their large eyes help them to find
and catch other water animals hiding between
water plants and in leaf litter. Adult
damselflies mainly eat flying insects that they
catch near the surface of the water.
More then 80 per cent of a damselfly’s
brain is used to make sense of things that
it sees through its eyes!
*All photos are taken from “Hawking, J.H. and Smith, F.J. (1997). Colour Guide to Invertebrates of Australian
Inland Waters (Identification Guide No.8). The Co-operative Research Centre for Freshwater Ecology, Albury.”

Dragonfly
Oder Odonta
Suborder Anispotera
Dragonfly larvae are sometimes called
mudeyes. They live on the bottom of
freshwater ponds and creeks, feeding on other
water animals that they catch by shooting out
their lower lip and dragging them in. When
the larvae are ready to turn into an adult
dragonfly, they climb up a water plant and
shed their skin before flying off. Dragonflies
have been found as fossils more than 300
million years old.
Adult dragonflies can fly at up to 50 km
per hour. They dart around above the
water to catch flying insects.
Stonefly
Order Plecoptera
Stonefly larvae live on the bottom of
freshwater streams and ponds and can often
be found resting on stones of fast-flowing
streams. The larvae are streamlined and
have claws on the ends of their feet so they
don’t get swept away. Most stonefly nymphs
feed on algae and dead plants while a few are
predators and feed on other water animals.
Many adult stoneflies only live for a few days
and some don’t even eat before they die!
Female stoneflies live longer than males.
*All photos are taken from “Hawking, J.H. and Smith, F.J. (1997). Colour Guide to Invertebrates of Australian
Inland Waters (Identification Guide No.8). The Co-operative Research Centre for Freshwater Ecology, Albury.”

Backswimmer
Order Hemiptera
Family Notonectidae
Backwimmers are predators, feeding on
smaller water bugs such as bloodworms and
insect larvae as well as insects resting on the
surface of the water. They breathe under
water by storing a bubble of air on the
underside of their body. If their watery home
becomes polluted or dries up, backswimmers
can fly to another pond or river.
Water Boatman
Order Hemiptera
Family Corixidae
Backswimmers get their name from their habit of
swimming upside down at the surface of the water.
Be careful because they can give you a nasty nip!
Water boatmen live amongst vegetation in
ponds and slow-flowing streams. These bugs
look similar to backswimmers except they
swim upright and prefer to feed at the bottom
of their habitat. They have sucking
mouthparts and feed on insects as well as
dead plants and animals in mud and leaf litter.
Water boatmen move through the water using
swimming hairs on their middle and back legs.
While resting, water boatmen cling to objects in
the water such as rocks and logs. Some even
hitch a ride on live fish!
*All photos are taken from “Hawking, J.H. and Smith, F.J. (1997). Colour Guide to Invertebrates of Australian
Inland Waters (Identification Guide No.8). The Co-operative Research Centre for Freshwater Ecology, Albury.”

Water Tiger
Order Coleoptera
Family Dytiscidae
Water tigers are the larvae of diving beetles
that live on the edges of streams and ponds.
They have a snorkel on the end of their bodies
that they stick out of the water to breathe.
Adult diving beetles breathe by storing air
under their wings. Water tigers feed on other
aquatic animals by injecting digestive fluids
into their prey and sucking out the liquefied
insides! Adults also eat water animals and will
even catch tadpoles and small fish. Water
tigers begin life as eggs which the female
beetles deposit in the stems of water plants.
Adult diving beetles fly from one water source to another by
looking for light reflected off the surface by the moon.
Sometimes they get confused and fly into street lights or the
headlights of cars!
Bloodworm
Order Diptera
Family Chironomidae
Bloodworms live in sludge on the bottom of
ponds and streams. They can survive in
water that is low in oxygen and are very
tolerant of pollution. They generally feed on
dead plants and animals while a few eat only
plants. Most bloodworms are free-living while
some live in silken tubes in the mud.
Bloodworms are red in colour because they
contain a substance called haemoglobin. This is
a blood protein that carries oxygen.
*All photos are taken from “Hawking, J.H. and Smith, F.J. (1997). Colour Guide to Invertebrates of Australian
Inland Waters (Identification Guide No.8). The Co-operative Research Centre for Freshwater Ecology, Albury.”

Caddis Fly
Order Tricoptera
The aquatic larvae of these flies enclose
themselves in cases of sand grains, twigs or
pebbles sown together with silken thread.
Others hide in hollow stems of reeds and
sedges while a few are free-swimming. Most
caddis fly larvae are found living on the bottom
of flowing creeks and rivers where they can
collect bits of algae and other plant material to
eat. The adult flies have wings and live on
land, usually near the water.
Mayfly
Order Epmeroptera
Like damselflies, mayfly nymphs have three
filaments, like tails on the end of their bodies.
They live under rocks and amongst plants in
rivers and creeks and feed on live or decaying
plant matter. The larvae breathe underwater
using gills and can take up to two years to
become adults. Adult mayflies have two pairs
of see-through wings and mate while flying.
Flat Worm
Class Turbellaria
Some caddis fly larvae in urban areas choose to build
their homes out of man-made structures such as drink
straws, pen lids and even lolly wrappers!
These flattened worms are common in
freshwater ponds and streams and have a
triangular-shaped head. They slide along the
bottom of their habitat, preying on other
invertebrates and scavenging on dead
animals. Some are parasites and feed off
larger animals. As well as reproducing
normally, flatworms can split themselves in
two, creating a new worm! This is called
asexual reproduction.
Adult mayflies live for no longer than 24 hours! They don’t
feed at all and mate as soon as they emerge from the water.
Flatworms don’t have bottoms so they
get rid of waste through their mouths!
*All photos are taken from “Hawking, J.H. and Smith, F.J. (1997). Colour Guide to Invertebrates of Australian
Inland Waters (Identification Guide No.8). The Co-operative Research Centre for Freshwater Ecology, Albury.”