Ecosystems
Topic 1 Continued: Using Energy
Part of the Local Ecosystems Module
Spotlight Biology Preliminary Text Chapter 4
Authors: D. Heffernan, J. Bastina, B. Grieve, K.
Humphreys, A. Sartor
Science Press 2002
Carnivores
Carnivores such as sharks and dingoes eat other animals
that have stored energy in the form of fats, oils and proteins.
australiangeographic.com.au
Animals that eat herbivores are called secondary
consumers and animals that eat other carnivores are called
tertiary consumers
Carnivores
Many meat eaters expend more energy than grazers in
actually obtaining their food. For example a lion stalking
and running down a zebra uses heaps of energy.
getfitstayingfit.com
Carnivores
Other carnivores, like trap door spiders, hide and wait to
ambush their prey. Therefore they may spend majority of
their time waiting for a meal to wander by.
flickr.com
Carnivores
Meat is easily digested and this is reflected in the anatomy
and behaviour of carnivores. Most carnivores hardly bother
to even chew their food. Their razer sharp teeth quickly
chop food into pieces small enough to be swallowed.
baynature.org
Carnivores
The chunks of meat contain heaps of energy which is
obtained in a much shorter digestive tract than herbivores.
Many meat eaters only need to feed occasionally, some like
crocodiles spend much of their time sleeping.
inquisitr.com
Omnivores
Omnivores like us and several other primates, eat plant and
animal material. Some vary their diets according to the
seasonal availability of preferred foods while others eat meat
and vegetable matter year around.
theveganpost.com
He teeth and digestive systems of omnivores combine the
characteristics of carnivores and herbivores.
Decomposers
Saprophytes obtain their energy by breaking down
(decomposing), the complex molecules in the decaying
tissues of plants and animals. These include fungi and
bacteria.
earth-cards.com
Decomposers
These organisms of decay are
vital to the health of all
ecosystems because they play a
crucial role in the cycling of
important nutrients. Without
these heterotrophs, the bodies of
dead animals would litter the
landscape and the nutrients
within them would be lost to the
ecosystem.
geekapolis.fooyoh.com
Other Feeding Techniques
Many feeding techniques do not fit into herbivores,
carnivores and or decomposers. Some herbivores and
carnivores are liquid feeders that only survive on liquids
extracted from their prey.
eyeswideblind.com
Other Feeding Techniques
Aphids and other sucking insects pierce plant stems and suck
out sugary sap. Mosquitoes attack animals the same way and
drink the blood of birds and mammals.
mossseo.wordpress.com
Spiders inject venom that liquefies its prey and then suck
with liquid up through a hollow tube.
Other Feeding Techniques
Another group is made up of the waste-feeders such as
dung beetles. These organisms feed on the waste or dung of
large animals.
ferrellgummit.wordpress.com
Other Feeding Techniques
Some of these animals live primarily on detritus, a
combination of bits of decaying organisms and dung
containing partially digested food. On land, detritus mixes
with soil particles and is eaten by earthworms and some
soil-dwelling insects.
publicdomainpictures.net
Other Feeding Techniques
Worms swallow large amounts of soil and digest the detritus
particles passing through their guts. A large number of
marine animals either filter floating detritus from the water
or pick it up off the bottom after it settles.
kids.britannica.com
Other Feeding Techniques
Aquatic environments offer several food sources not found
in terrestrial environments. In addition to floating detritus,
water carries many dissolved organic molecules. Both fresh
and salt water harbour tiny floating or swimming plants
called phytoplankton (phyto: plant, plankton: drifter) and
animals called zooplankton (zoo: animal).
gtresearchnews.gatech.edu
Other Feeding Techniques
To make use of such foods, many marine species are filter
feeders, with mouth parts, gills and specially designed limbs
that filter the water to obtain food from around them.
Video
http://www.youtube.com/watch?v=vNqEQjGaDVk
messersmith.name
Homework
1.
2.
3.
4.
5.
6.
Explain why decomposers are so vital to ecosystems
If you were an earthworm, what would be on the menu?
Explain.
Compare phytoplankton with zooplankton
Some whales use baleen plates to sift krill from ocean
water. Classify the type of feeding used by these whales.
Suppose that all phytoplankton die in an epidemic. Predict
what effect it would have on the environment.
Classify the following as herbivores, carnivores or
omnivores: flying fox, fox, ring-tailed possum, wombat,
bee, wasp, leech, mosquito.