Cattle Egrets and Grazing Animals
Cattle egrets forage in fields among buffalo, cattle or other livestock. As cattle, horses and other
livestock graze on the field, they cause movements that stir up various insects. As the insects are
stirred up, the cattle egrets following the livestock catch and feed upon them. The egrets benefit
from this relationship because the livestock have helped them find their meals, while the livestock
are typically unaffected by it.
Cleaner Wrasse and Fish
The cleaner wrasse, one of 600 species of wrasse, is found along coral reefs worldwide and usually
choose a home along the reef that is popular among fish to set up its cleaning station. At this
location, various fish literally line up and wait to be "cleaned" by the wrasse. This is one of the few
cases in which varying species of fish actually inhabit the same space without becoming territorial or
aggressive with each other. It's clear that these fish have one thing on their mind when they line up
at the cleaning station: getting the parasites removed as soon as possible. Easily distinguished by a
bright blue and yellow band, the cleaner wrasse makes an effort to advertise its services by
performing a dance. Likewise, when a fish wants to be "cleaned" it sends specific signals to the
wrasse, such as keeping its body stationary, while spreading its fins and gills and opening its mouth.
If the wrasse picks up on the signal it will begin the cleaning process on its customer, which is
usually a larger fish. Cleaning consists of the wrasse swimming over the entire body of its customer,
eating parasites from the fins and gills. The wrasse will even go inside the mouth and clean between
the teeth of its customer. Interestingly enough, the wrasse is rarely injured or eaten by the other fish;
the wrasse vibrates its fins while cleaning to remind its customer of its presence. Moreover, the
cleaned animal will frequently defend the cleaning station and its cleaners from attack by would-be
predators
Caterpillar Wasp and the Caterpillar
The caterpillar wasp captures a caterpillar but does not eat it. Instead it lays dozens of eggs then
flies off to find another caterpillar. Within days the eggs hatch and burrow through the caterpillar’s
skin and into its flesh. As they grow the maggots develop mouthparts and begin to eat away at the
caterpillar’s muscles, organs and viscera. By the time the wasp larvae (maggots) are large enough to
emerge from their unwilling host the caterpillar is nothing but a hollowed out shell. Soon the larvae
will form pupae (cocoon), go through metamorphosis and emerge as an adult caterpillar wasp eager
to mate and find another unwilling thrall to serve as a gruesome nursery for its carnivorous
offspring. Muhahahaha….
Remora and Shark
The host to which it attaches for transport gains nothing from the relationship, but also loses little.
The shark is unharmed by the remora’s suction cup dorsal fin by which it attaches. The remora
benefits by using the host as transport and protection, and also feeds on materials dropped by the
host. Controversy surrounds whether a remora's diet is primarily leftover fragments, or the feces of
the host.
Roundworms and Humans
Roundworms are an intestinal parasite that can infect people if they eat meat or drink water
contaminated with roundworm eggs. The roundworms usually live in the intestines of livestock but
people who live in rural villages in South America, Africa and Asia where animals and people live
in close proximity are most at risk of becoming infected. Without proper sewage systems and water
purification systems animal feces may contaminate the local well, stream or river where people get
their water. Once inside the human intestines the eggs hatch, grow and multiply by eating the food
present in the intestines. With a severe enough infection, a person could eat a healthy diet but starve
since the food never gets absorbed into the bloodstream. Roundworms can make their way into a
person’s bloodstream and wind up infecting the eyes causing blindness. As a person sleeps,
roundworms could migrate up their esophagus and emerge from their mouth and nose in search of
food. If they move down the trachea into the lungs a person could die.
Clown Fish and Sea Anemone
Clownfish have a slimy mucus covering that protects them from the sea anemone. However, if this
covering is wiped off of a clownfish, it will get stung and possibly be killed when it returns home to
the anemone. The clownfish and the sea anemone help each other survive in the ocean. The
clownfish, while being provided with food, cleans away fish and algae leftovers from the anemone.
In addition, the sea anemones are given better water circulation because the clownfish fan their fins
while swimming about.