BBC - GCSE Bitesize: Parasitism and mutualism
the tapeworms feed o the animal. What is an example of a parasitic relationship between an animal and a plant? Views · What is the Is there a symbiotic relationship between humans, animals and the environment?. Symbiotic relationships are very important in nature and happen all around us. and Humans • Leeches are worms that suck blood from animals including. For Higher Biology, revise different types of symbiotic relationships in animals.
Many types of parasites carry and transmit disease. Lyme disease is trasmitted by deer ticks. A parasite and its host evolve together.
The parasite adapts to its environment by living in and using the host in ways that harm it.Extreme Animal Relationships - Earth Unplugged
Hosts also develop ways of getting rid of or protecting themselves from parasites. For example, they can scratch away ticks. Some hosts also build a symbiotic relationship with another organism that helps to get rid of the parasite.
Ladybugs live on plants, eating the aphids and benefiting by getting food, while the plant benefits by being rid of the aphids. The tick could transmit disease to the host. Mutualism — both organisms benefit. In return, the clown fish clean debris from the sea anemone.
Parasitism and mutualism
When a leech comes in contact with a human, it attaches to the skin with a suction cup shaped mouth. The Leech sucks blood from the human.
The leech receives a meal, while the human loses a small amount of blood. The leach may also leave a small wound. Once a tapeworm enters a host it will attach itself to the digestive tract of the host and feed off the food that the host ingests. The tapeworm is not feeding on the host, but is stealing nutrients from the host.
This can lead to sickness, malnutrition, digestion problems and even death for the host. This allows for the birds to be safe from predators. The tree at lower left is absolutely covered with epiphytes. Leeches below left are usually thought of as ectoparasites although some are predators. They attach to a vertebrate host and take a blood meal before dropping off. Most aren't adapted to a single vertebrate host, but they are highly adapted to sucking blood; their saliva includes anesthetics to help keep the host from noticing the bite, as well as anticoagulants to keep the blood flowing.
Tapeworm and cow
Below is a larval mussel freshwater clam. If there is any case of "good" parasitism, this may be it. The little mussels go into the mouth and pass over the gills. Here, they clamp down by closing the shell and digging in with the little teeth pictured at the edge of the shell. The fish provides a meal and transport upstream moving is not something mussels do well over long distances, particularly upstream. Lichens above and left are mutualistic associations between a fungus and an algae or cyanobacteria.
They are the terrestrial equivalents in some ways of corals. The fungus provides a tough, waterproof body able to withstand extreme environments on rocks and tree trunks. It is good at obtaining water and secretes acids to dissolve minerals from the rocks. It also produces carbon dioxide. All of these materials are then funneled to the endosymbiotic algae or cyanobacteria, which use the materials in photosynthesis and produce sugars which are then shared with the fungus.
Some studies have shown that the fungus benefits from this relationship more so than the algae; at least under good conditions algae grown without the fungus grow faster then they do with the fungus. This wasp has stung and paralyzed a stink bug and is dragging it to its underground lair.
Here it will deposit an egg and the larvae that hatches from the egg will eventually consume the bug. Keeping the bug alive but paralyzed ensures it doesn't rot.
The two lice to the right parasitize humans. The body louse above can attach to hairs of the body or head and then suck blood from the host. While it is relatively easy to remove the adults particularly if your hair is thinthe eggs are another story.
The eggs are called nits and are glued to the hairs, the careful search for these tiny eggs has given us the term "nitpicking". The larger claws of the crab louse allow it to grasp the thicker pubic hairs. Overall, lice aren't the biggest health concenr humans face; on their own they do relatively little damage. The diseases they can transmit, however, can cause devastating epidemics and many deaths.
Fleas below are adapted to live in mammals with thicker hair. The comb-like structures help them hang on.
BBC Bitesize - Higher Biology - Symbiosis - Revision 1
The mosquito above is a very temporary exoparasite; it probably shouldn't be counted as a symbiont so much as a predator. Not all situations are readily apparent. The mites on the bumblebee at left are in fact sucking fluids from it; mites have been implicated in the decline of our commercial honeybees.
This is a clear case of ectoparasitism. On the other hand, the mites in the image above left are merely hitching a ride on the Carrion Beetle. This beetle locates dead animals and flies to the carcasses to lay its eggs, which hatch and feed on maggots on the carcass.
The mites are interesting. Often, they feed on fly eggs and small maggots; this reduces competition for the carrion by the flies, and thus actually helps the beetles out a bit. The mites do NOT suck fluids from the beetle; they merely hitch a ride and thus make a trip they would not be able to make on their own.
This hitchhiking is called phoresy, and as long as the phoretic animals are much smaller than their hosts - and there aren't too many of them - this would qualify as a commensal relationship.
If the mites help to reduce the maggot population and thus reduce competition for the beetle, they may actually be benefiting the beetle and thus move this relationship into mutualism. Right - A leafcutter ant tending fungus in its underground nest. The fungus is almost completely dependent on the ants. The ants bring in nutrients bits of plant leavesprune the fungus back, transfer it to new bits of leaves and even to new ant nestsremove competing fungi, bring in only leaf bits from trees without chemicals which would hurt the fungus, etc.
Perhaps most amazing is the fact that the ants enlist a second symbiont - bacteria of the genus Streptomyces that the ants grow in specially modified areas of their own exoskeletons. The Streptomyces is then used to produce antibiotics that inhibit the growth of fungi which would compete with the fungi the ants are growing. There is a lot more to this mutualistic interaction; try this page built with pictures from our Costa Rica trips: We call these organisms Keystone species 1.
Keystone predators may control key competitors at lower levels in the food chain, thus allowing other species to thrive. Keystone mutualists may provide needed resources for a wide host of organisms example: Keystone competitors, if removed, allow one competitor to dominate, reducing diversity The Gopher Tortoise above and right is a classic example of a keystone mutualist. It excavates large burrows which may extend 10 meters or more, and which are almost 1 foot in diameter with some larger chambers as well, so the turtle can turn around.
A number of other species including burrowing owls, gopher frogs, indigo snakes, and a number of invertebrates are highly dependent on these burrows; they often live in the burrow alongside the tortoise benefits to the tortoise of this arrangement are not clear.
Studies of the Purple Sea Star Pisaster ochraceus have shown it to be a keystone predator - it preys preferentially on species - such as certain mussels - which would otherwise outcompete all the other species trying to gain a foothold on the rocks.
By reducing the number of mussels, the sea stars open up habitat for other species and thus increase the overall diversity of the ecosystem note that the sea stars are a predator to the mussels, not a mutualist! The Red Mangrove, below, has long stilted roots that arch down to the water at the edge of tropical shores.
These roots stabilize the soil, protect coastal areas from erosion, and provide hiding places for many animals, including the young of many coral reef fish.
In this way the Red Mangrove is a keystone mutualist like the Gopher Tortoise. The American Alligator, left, excavates depressions in its habitat that fill with water.