Sunday, April 17, 2011

Yellow Watchman Goby and Tiger Pistol Shrimp: Best Friends for Life

[1]

Introduction:

Many species on this earth have evolved to create very unique relationships with each other. One of the most unique relationships is that of the shrimp and goby. These creatures have a mutualistic relationship with each other and is it suggested that without one another, they would not live very long. Together, they live in a burrowed out home usually found on the sandy ocean floor. While the shrimp digs out the home, the goby stays watches out for the blind shrimp like a watchdog. Through the cooperation of both, these creatures thrive in the scary world of the ocean.

The goby fish are from the family Gobiidae. This family of fish contains 2,200 species of fish. [2] . Many of these gobies are known to have the mutualistic relationship with the shrimp.A perfect example of this relationship is the relationship of the yellow watchman goby, or the Cyrptocentrus cinctus, and the tiger pistol shrimp, or the Alpheus bellulus. The yellow watchman goby is a yellow colored goby and the tiger pistol shrimp is a tanned bodied shrimp that is characterized with rust colored broken stripes running across their backs. [3][4]











These creatures can be found in sand flats on coral reefs and shallow lagoons and can reach a depth of 3-50 ft. Often, their homes are found under rocks or coral reef rubble. Typically, these creatures can be seen inhabiting shallow sea floors in parts of the Pacific Ocean and the Red Sea. [6]

The yellow watchman goby reproduces sexually; they undergo usual fish-sexual means of reproduction (fertilizing eggs, laying eggs, eggs hatching, and young growing into adults). The lifespan of this species of fish is usually 5 years. [7] The adult gobies are known for making this mutualistic relationship with the shrimp.

The tiger pistol shrimp reproduce sexually. From the laid eggs, they develop into adults. As with the gobies, the adults are the ones known to make this unusual relationship. The typical lifespan of this shrimp is from 5-8 years. [8]

The Relationship:

One of the reastons as to why the yellow watchman goby and the tiger pistol shrimp have evolved this interesting relationship, is because this particular species of goby are horrible burrowers and the tiger pistol shrimp are blind. Both of these traits, without help, can lead these organisms to being an easy prey. When combined together, they almost complete one another: This goby in opposite to the shrimp can see and the shrimp are wonderful burrowers. It is because of these traits that these two creatures have adapted to living together.

Looking at the relationship, the shrimp burrows out a home for the goby, while the goby watches and looks out for the shrimp and itself. During the day, the goby keeps watch outside of the home and will protect the shrimp if it wonders out for a meal. At night, both the shrimp and the goby sleep together peacefully in the house. [9] Occasionally, 2 gobies will live in the same home with the shrimp.


The way the goby protects the shrimp is through the shrimp's and the goby’s communication. When the shrimp emerges from the burrowed home, they do not wonder far. They try to stay around the hole leading down to their home. The shrimp uses their antennas to make sure they do not stray far from the goby. The shrimp keeps their antenna in contact with the goby’s tail and can feel the goby and they know whether or not they go too far. The goby keeps watch for both of them. If the goby senses danger, it will flicker its tail. The shrimp will receive the alert and will either retreat back into the home or stay still. If danger is bad enough, the goby will dive head first into the burrow, but when this happens, the goby always follows the shrimp in. If the shrimp strays too far from the home, the goby will stay with it and will lead the blind shrimp back. [3][11]


One of main questions is as to how these organisms go about finding each other? It has been suggested that the goby is attracted to the sight of the blind shrimp while the shrimp is chemically attracted to the goby. This means if the shrimp senses any chemicals that are related to the said goby, they will make their way to them. With the goby, if the goby sees a blind shrimp or their burrow, they will swim their way to them. Either way, they will find each other and will set up their mutualistic relationship. [13]

Benefits:

The benefits of the shrimp are that they receive protection from any harm and will be granted a guide through the scary seawaters. The benefits of the goby are that they have a home and will not have to worry about the home falling in because of the shrimp’s constant maintenance of the home. In this, they receive shelter. Also, the tiger pistol shrimp is known to share its food with the goby. [14]

Costs:

The costs of the shrimp are that they cannot live without the guidance/protection of the goby. Because they are blind, they are completely reliant on the goby’s guiding and their protection. The goby in return cannot burrow a hole properly. Without the shrimp, they would have to find alternative methods of a home. In most places in the ocean world, an empty hole would be hard to find. The goby is almost completely reliant on the shrimp for finding a home.

Videos:

[14]



[15]
Sources:

1. http://www.advancedaquarist.com/2011/1/fish
2. http://www.britannica.com/EBchecked/topic/236587/goby
3. http://www.reeftime.com/profiles/gobies-blennies/yellow-watchman-goby/100024.htm
4. http://www.midwestmarineguy.com/marine-life-kb/invertebrates/id/tiger-pistol-shrimp
5. http://hubpages.com/hub/pistol-shrimp
6. http://sea.sheddaquarium.org/sea/fact_sheets.asp?id=81
7. http://www.fishforums.net/index.php?/topic/224606-yellow-watchman-goby/
8. http://www.theaquariumwiki.com/Alpheus_bellulus
9. http://www.liveaquaria.com/PIC/article.cfm?aid=201
10. http://www.flickr.com/photos/mlhamilton/3318444956/
11. http://blog.nus.edu.sg/lsm2251student/files/2010/04/Goby-Shrimp-Interaction.pdf
12. http://reefbuilders.com/forums/reef-discussion/11470-shrimpgoby-pink-blue-pistol-shrimp.html
13. http://www.explorebiodiversity.com/Hawaii/Shrimp-goby/general/Pair%20Formation.htm
14. http://www.indyzoo.com/SiteAssets/pdfs/YellowWatchmanGoby.pdf
14. http://animal.discovery.com/videos/top-10-odd-animal-couples-shrimp-a-goby.html
15. http://www.youtube.com/watch?v=j-WoVNs62KE

Friday, April 15, 2011

Toxic Beauty

Introduction

One never fails to notice the beauty and innocence of a monarch butterfly. It does not try to hurt anything or is associated in any negative way, just something pretty to look at on a beautiful spring day…right? It will come as a shock to you when I describe how it is filled with toxic substances that will harm animals that try to eat it!

The monarch butterfly (Danaus plexippus) in the larval stage feeds on species of milkweed (Asplepias) [2]. It is the host plant for almost the entire monarch’s lifecycle. Milkweed is a type of sprouted plant that contains “milk” which is white latex. The “milk” is acidic and poisonous to many animals. The monarch from larval stage to caterpillar does not eat anything but the milkweed milk, meaning that it absorbs these compounds into its body and will store them all throughout its lifetime. This will cause harm to any animal trying to eat the not so innocent butterfly. They are found all throughout the world beginning in June till about late summer or early fall. The monarch butterfly is one of the fewbutterflies that migrate south during the cold weather [5]. The interesting ability to use the milkweed to synthesize the bitter substance within has allowed the monarch butterfly to be one of the most recognized and successful animal species.

Description of the Relationship

The monarch is fully dependent on the milkweed, where one finds a monarch butterfly there will most certainly be milkweed around. This relationship with milkweed is unique, not every butterfly can synthesize and take in the milkweed poison. This is because milkweeds contain alkaloids called cardiac glycosides, which make the plant taste bad and the monarch poisonous [4]. Milkweed belongs to the genus Asclepias, there are many species within Asclepias that monarch’s use. The common milkweed is Asclepias syriaca. The monarch butterfly belongs to Danaus plexippus. A female monarch butterfly will lay its eggs on the underside of the leaf of a sprouted milkweed plant. The eggs are about the size of a typed period on this page! About three to ten days later a tiny caterpillar with yellow and black stripes will hatch. It will eat the egg casing and then eat large amounts of milkweed very quickly. As the caterpillar grows from eating, it has to shed its skin four times to allow for that rapid growth to occur. At the final stage the larva is about 5 cm long; this growth rate is huge! Imagine a human baby growing that fast…it would be bigger than a school bus in the same amount of time [8]!

After it eats for about two weeks non-stop it looks for a place to pupate. It hangs down in a “J” under a branch or ledge. After about one to two days inside, the caterpillar will change into a green chrysalis with gold spots. Then in about one to three weeks the chrysalis will become transparent with the case thinning out. The monarch butterfly will emerge out. The monarch butterfly will have strong wings because they migrate, so in the beginning as a butterfly, large amounts of liquid is pumped from the body to the wings. The male butterflies are distinct from the females in that they have a black spot in the third vein of each hind wing. This spot produces perfume that attracts a female. Now as an adult butterfly, they can drink any type of nectar not just specifically milkweed, whereas in the larval stage they can only feed on milkweed. The butterfly in the larval stage took in enough milkweed poison to last for its entire life. Therefore, birds and other predators have learned to stay away from monarch butterflies [2,8].

Looking from the perspective of the milkweed, the monarch help the plant pollinate its seeds. This serves as a benefit to the plant, therefore making this a mutualistic relationship. The monarch benefits with food and shelter while the plant receives pollination. However, pollination can occur with other types of butterflies, bees, ants, and moths, not just specifically monarch butterflies [4]. But monarch butterflies cannot feed at the larval stage on anything but the milkweed. The monarch, therefore, is in an obligated relationship with the milkweed.

The need for continual change for survival and reproductive fitness as the Red Queen Hypothesis states has allowed an interesting co-evolutionary relationship to develop between the monarch butterfly (Danaus plexippus) and viceroy butterfly (Limenitis archippus). The evolutionary arms race has created a mimicking version of the monarch to reap the benefits of the appearance. Birds or any other predator preying on butterfly know to stay away from the monarch. The vibrant appearance gives the predator a hint to stay away. This type of mimicry is called batesian mimicry. The harmless species (viceroy butterfly) has evolved to imitate the warning signals of a harmful species (monarch butterfly) [3]. Take a look and see if you can tell the difference.

Can you see the difference?









(On the left is a viceroy butterfly, the right is a monarch butterfly)

Cost/Benefits Analysis

Monarch butterfly’s entire existence depends on the milkweed. If one day there were to be no milkweed the caterpillar would have no food and would not survive. This dependency can constitute as a cost to the monarch, this is one of the reasons why the monarch population is dwindling. The use of transgenic crops is killing the milkweeds and is not allowing the monarch caterpillar to have a place for food and protection [2]. Unless some evolutionary adaption occurs where the monarch larvae have another source of food, these butterflies may not be around anymore.

There are also some scenarios where there is a cost on the milkweed due to the caterpillar. The caterpillar is harming the plant when feeding at large amounts on the leaves. However, this does not reduce the ability of reproductive success of the plant and the plant has adapted the ability to repair itself. Although some argue that the repairing still sets a cost on the plant where energy is lost. The other side of the situation is the monarchs actually help the plant pollinate [1]. Both the milkweed and butterfly are benefiting from each other. Whichever the case the relationship will only continue to exist as long as the milkweed plants are around.

So beware to predators preying on the beautiful and “naive” monarch butterfly! Consuming will cause harm!

References

[1] Agrawal, Anurag. "Researcher Shows Evolution of Milkweed Defense System." PhysOrg.com - Science News, Technology, Physics, Nanotechnology, Space Science, Earth Science, Medicine. Web. 13 Apr. 2011.

http://www.physorg.com/news135960491.html

[2] Ames, Doris. "Milkweed and Monarchs." Native Orchid Conservation Inc. Web. 13 Apr. 2011 http://www.nativeorchid.org/dorisMandM.htm

[3] "Co-evolution and the Evolutionary Arms-race." WVU Parkersburg. Web. 13 Apr. 2011 http://www.wvup.edu/ecrisp/biolgeol397co-evolution.html

[4] Froehlich, Shirley. "Milkweeds & Monarchs." Prairieoriginals. Web. 13 Apr. 2011

http://www.prairieoriginals.com/MILKWEEDS.pdf

[5] "Monarch Butterfly and Milkweed." Monarch Butterfly and Milkweed. 12 Oct. 2001. Web. 13 Apr. 2011.

http://ed.fnal.gov/entry_exhibits/insect/monarch.htm

[6] "Monarch." The World of the Butterfly | Why Butterfly. Web. 13 Apr. 2011.

http://whybutterfly.com/

[7] Pratt, Jim. "Life Cycle of the Monarch Butterfly." Zimbio. 30 June 2010. Web. 13 Apr. 2011.

http://www.zimbio.com/Butterfly+watching/articles/VHpUYG1KslL/Life+Cycle+Monarch+Butterfly.

[8] "The Monarch Butterfly." Kidzone - Fun Facts for Kids! Web. 15 Apr. 2011 http://www.kidzone.ws/animals/monarch_butterfly.htm

Ants & Aphids



http://www.hiltonpond.org/ThisWeek070701.html


Introduction

Aphids are distributed worldwide, but mainly in temperate zones. They produce asexually; females can produce up to 12 offspring a day. These populations sometimes have the ability to increase rapidly. In good conditions, newborns can develop into reproducing adults in less than two weeks. [1] Ants are well-known protectors of aphids. They feed off of honeydew they produce, and in return, protect them from parasites and other predators. [2]


Description of Relationship

Aphids are of the superfamily Aphidoidea. They feed on phloem sap, which is high in sugar but low in nitrogen. This requires them to ingest high amounts of the phloem sap, which in turn causes them to excrete a substance called honeydew through their anus. This substance is very sweet, containing excess sugar from their diet. Not all ants have relationships with aphids, but some ants feed off of this substance. Worker ants of subfamilies Formicinae and Dolichoderinae, along with some species in genus Myrmica and Tetramorium collect the honeydew. [5] They provide protection for the aphids by protecting eggs during the winter, and transporting newborns to host plants. Here, the newborn aphids feed on the plant leaves, providing honeydew excretions for the ants. [3] Ants really take care of the aphids, leading them to new food sources when needed, and defending them in the case of predators.

Sometimes, ants will even stimulate the aphids by using their antennae to stroke them, encouraging them to produce the honeydew. This can cause aphids to lose the ability to release waste on their own, making them dependent on the ants for this reason.

However, as with any mutualistic relationship, ants really are looking out for themselves. They protect the aphids only because they need the honeydew. For example, while aphids are usually wingless, they are sometimes able to produce wings. If needed, they can fly away from poor environmental conditions, or find new food sources. Because ants do not want the aphids to leave, they have sometimes gone to extreme measures to keep the aphids around. They release chemicals to prevent wing development, or in worse situations, even destroy the already-developed wings. [2]

It has been indicated that these associations were in existence as far back as the early Oligocene. The prevalence of ant relationships does not seem to change among different groups of aphids. [5]

This relationship is an example of mutualism. Mutualism is defined as a relationship between two species who associate with each other so that each benefits. Instead of one partner exploiting the other without reciprocity, each partner exploits the other. In this relationship, the ants exploit the aphids in order to receive the honeydew, and the aphids use the ants as a means for protection they could not provide themselves. [4]


Cost/Benefit Analysis

Aphids

Cost: Aphids can be damaged by ants trying to destroy their wings, and also can become dependent on ants for excretion of honeydew. [2] By increasing intake of honeydew in order to attract ants, aphids reduce efficiency and therefore reduce growth rate. [5]
Benefit: protection from parasites and other natural enemies [5]


Ants

Cost: Morphological/behavioral adaptations necessary to collect and transport honeydew to nest mates. Another cost is dependence on aphids for fuel.
Benefit: Getting honeydew from aphids - food source [5]


http://www.youtube.com/watch?v=Dhi-SYxNPFw



References

[1] http://www.uri.edu/ce/factsheets/sheets/aphids.html
[2] http://insects.about.com/od/coolandunusualinsects/f/antsandaphids.htm
[3] http://science.jrank.org/pages/462/Aphids-Ants-aphids.html
[4] http://www.jstor.org/stable/2647385
[5] http://www.annualreviews.org/doi/full/10.1146/annurev.ecolsys.36.091704.175531

Wednesday, April 13, 2011

Bacteria in the guts are good for you?

Introduction:

Termites have roamed the earth since the time of the dinosaur yet most species have not yet developed a way to digest cellulose on their own [1]. Millions of years ago, termites learned that a bacterium in their gut could help them break down the cellulose and plant fibers that they eat [2]. Since then termites and Trichonympha have lived in a symbiotic relationship with one another. Most ever species of termites share

a relationship with the bacterium Trichonmympha and because termites are found worldwide, and mostly in tropical areas, so is their bacterium [3].

The life cycle of a termite is depended on two things: the species and the environment. Some species live longer than others and some environments support termite life better than others. Warmer climates allow termites to live a longer life [4]. A queen termite in some species can live for a decade or more while a worker or solider termite has a life span of one to five years. A termite goes through three stages of development. Eggs hatch to reveal nymphs from there two different types of termites develop: the worker

termite and the solider termite. Both types continue to molt and form into the adult termite. Due to termites having incomplete metamorphosis, both worker and solider termites grow wings. This stage with wings is called the alates stage. The termites continue to grow and they shed their wings. From there a king and a queen termite mate and the female lays more eggs to continue the cycle [5].

Termite nymphs are not born with the bacterium Trichonympha but rather they must be infected with it from one of the older termites. Every time a termite molts it must infected again in order the termite to survive [6].


Description of Relationship:

Most species of termites and the bacterium Trichonympha, from the genus parabasalian, have a mutualistic relationship, meaning that each benefits from the other. The termites are placed in a category of eusocial insect meaning that they raise their young as a group [7]. As a nymph, these termites are white in color and are thus referred to as “white ant” [2]. The colonies of termites consist of two different forms of termites. The worker termite is blind, wingless and sterile. It is unpigmented, soft, and works in dark moist areas. Worker termites are needed to build nests, get good, and feed the solider termites. The solider termites are every bit the same in appearance as worker termites except solider termites have a hard cuticles rather than soft ones and they have a brown head rather than a white one. Solider termites also have large mandibles that allow them to defend the colony against intruders [8]. King and queen termites have wings that are twice the size of their bodies and their main job in the colony is to reproduce [9].

Trichonympha inside the gut of the termite helps the termite digest cellulose and plant fibers that the termite could not digest on its own. This adaptation has allowed termites to survive for millions of years while allowing the bacterium to continue developing. The bacterium inside the termite engulfs the eaten wood or plant substances and uses a bacterium of its own to break it down.

Cost/Benefit Analysis:

Termite

  • Cost: must be infected with bacterium in order to survive
  • Benefit: bacterium helps termite get its food digested

Trichonympha

  • Cost: they have to live inside termites otherwise they cannot make cellulose for their own self
  • Benefit: termites provide food and shelter [10].


References:

[1] http://www.pestworldforkids.org/termites.html

[2] http://en.wikipedia.org/wiki/Trichonympha

[3] http://www.springerlink.com/content/p439l941w617627q/

[4] http://www.termiteweb.com/the-typical-termite-life-cycle/

[5] http://termite-control-protection.blogspot.com/2010/09/subterranean-termite-reticulitermis.html

[6] http://www.mrcroft.com/notes/ecology/Termite%20Symbiosis%20Lab.pdf

[7] http://en.wikipedia.org/wiki/Termite#Diet

[8] http://www.fzi.uni-freiburg.de/InsectPestKey-long%20version/termit2.htm

[9] http://www.allmaxpestcontrol.com/Termite.html

[10] http://wiki.answers.com/Q/Why_do_termites_need_bacteria

Monday, April 11, 2011

Follow the Leader


INTRODUCTION: Cattle are found on every continent in the world except that of Antarctica [1]. They are grass eating ruminants that provide milk and beef to people across the world [3].TheBubulcus ibis, or more commonly known as the Cattle Egret, is a type of heron. They feed exclusively on insects such as grasshoppers and crickets. These birds are originally from Africa and Asia, but can now be found in North and South America [2]. They are of medium size for a bird with a swollen throat, dark legs and feet, and short thick necks [2].These herons, along with various sub species of Bos primigenius, engage in a commensal relationship Where there are cattle, or even lawn mowers, there are Cattle Egrets. These birds will follow just about any animal or object that disturbs grasses where they feed.

RELATIONSHIP: The cattle Egret is a forager, following or riding on grazing animals and eating the insects that are aroused by the grazing cattle [2]. They can sometimes be seen hunting like other birds, but most commonly they follow cattle and what is stirred up [4]. The cattle typically do not gain anything from their interaction with the birds; they simply go about their grass eating. The key word here is typically. The Cattle Egret has been observed perched on top of cattle eating insects and or parasitic threats to the grazing animals [4]. This makes this relationship partly materialistic. Sometimes the birds are seen gaining food while simultaneously providing protection for the cattle, however more times than not, this is not the case and the cattle neither benefits or is harmed by this interaction.

COSTS AND BENEFITS: The costs and benefits for both participants of this relationship are minimal.

Cattle Egret: Cost: Egret is dependent on cattle for primary source of food. Benefit: Egret saves energy by not expending it on searching for food. Why benefit outweighs cost: The cattle egret typically has a clutch size between 1 and 9 [2], but many times the egret parents cannot keep up with the feeding demands of all their young and several may die [4]. It thus becomes extremely important for the Egret to conserve as much energy as possible so that the maximum number of offspring can carry genes to the next generation.

Cattle: Cost: Having a small animal stalk you all day. ARKive video - Cattle egrets following African elephants to catch flushed out prey Benefit: Every once in a while having the Egret eat something that is attempting to eat you. Why the benefit outweighs the cost: Even though the Egret hardly ever is found picking bugs off of the cattle themselves, it could happen, which would undoubtedly be a benefit of pest protection. But since the birds don’t cost the cattle anything, and cattle don’t eat birds, it is not worth the energy of the cattle to attempt to get rid of the birds.

1. http://earthtrends.wri.org/text/agriculture-food/map-245.html

2. http://www.allaboutbirds.org/guide/Cattle_Egret/lifehistory

3. http://www.strausfamilycreamery.com/?id=72

4. http://animals.howstuffworks.com/birds/egret-info.htm

5. Video: http://www.arkive.org/cattle-egret/bubulcus-ibis/video-03a.html

Pompeii Worms and Proteobacteria: Voted Hottest Couple

Introduction:
In high school there's always one couple that seems so perfectly matched, like the typical star quarterback and head cheerleader relationship. He carries her heavy books to class and she brings him ice cold water to practice. These types of people win prom king and queen in every cliche movie and will inevitably live happily ever after. The natural world also has its own superlative categories. Alvinella pompejana, commonly referred to as the Pompeii worm, is an extremophile polychaete that resides in the East Pacific Rise hydrothermal vents deep in the Pacific Ocean [1]. In this environment, temperatures can be as hot as 176ยบ F and the five inch worm is still able to survive [2]. It is the most heat tolerant animal and can have a broad temperature gradient along its body. Tentacle-like gills adorn the A. pompejana's head as if to crown itself with the title "hottest creature on earth." Despite the Pompeii worm's adaptations to extreme environments, thermal vents are unstable habitats so the worms are probably inclined towards methods of dispersal with large numbers of offspring. However, like most deep sea vent creatures, the full life cycle of the Pompeii worm remains unknown [3].

[4]

Pompeii worms insert their tails into the side of the vents, leaving their head exposed to the milder waters of 72°F [5]. How is the worm able to tolerate such a range of temperatures? The secret lies in a fuzzy hairs along the Pompeii worm's body. The "fleece" is actually bacteria.

[6]
Colonies of filamentous Proteobacteria form a protective coating over the worm's mucus glands [7]. It's not quite a letterman's jacket that the previously mentioned football star would give his cheerleader girlfriend. In fact, it's a more profound mutualistic relationship.


Description of Relationship:
The bacteria and A. pompejana are protected from the extreme heat by enzymes in the epibacteria. Some research indicates that the bacteria serves as thermal insulation [1]. In return, the Pompeii worm secretes a mucus that the bacteria lives and feeds upon [3]. This relationship has evolved to a level of morphological functionality. The bacteria and the mucosal secretions are part of the worm and contribute to protecting it from the vent temperatures [3]. Metabolic processes for the worm may also depend on the bacteria because of the extreme conditions in their habitat. The bacteria can transform inorganic substances into usable sources of energy, and thus helping the worm survive nutritionally as well.



Cost/Benefit Analysis:
Both organisms benefit from the other, the worm gains protection and sources of energy, while the bacteria gains a place to live and sustenance (Pompeii worm mucus). The worm encourages bacteria attachment by secreting the mucus, so the costs of housing the worm are outweighed by benefits. Diversity of life in the hydrothermal vents is very small, due to the lack of organismal adaptations to such conditions. Extremophile bacteria's reliance on the Pompeii worm is purely beneficial.


References:
1. http://en.wikipedia.org/wiki/Pompeii_worm
2. http://aem.asm.org/cgi/reprint/63/3/1124
3-http://www.jmst.org.tw/marine/15-2_1/37-53.pdf
4. http://ursispaltenstein.ch/blog/images/uploads_img/deep_sea.jpg
5. http://wapedia.mobi/thumb/3ad1500/en/fixed/470/300/Grand_prismatic_spring.jpg?format=jpg
6. http://alvinella.igbmc.fr/Alvinella/images/alvinelle.jp
7. http://www.ceoe.udel.edu/extreme2003/creatures/pompeiiworm/index.html/biologylibrary.blogspot.com/2010/06/hot-hydrothermal-vents.html
8. http://microbewiki.kenyon.edu/index.php/Deep_sea_vent
9. http://aem.asm.org/cgi/reprint/63/3/1124
10. http://web.uvic.ca/sciweb/images/hydrothermal-vent.jpg
11. http://www.bbc.co.uk/nature/images/ic/credit/640x395/p/po/pompeii_worm/pompeii_worm_1.jpg

Thursday, April 7, 2011

You Look This Way, I'll Listen That Way


Introduction
Oxpeckers are not the only birds that zebras have been known to pair with – they also are often found in the company of ostriches. Both of these species are justifiably concerned with approaching danger [1]. Equus burchellii, more commonly known as the plain zebra, is geographically widespread. They are social animals that spend time in herds. Zebras must be constantly wary of lions and hyenas. They travel in herds so more eyes are on alert for danger. If an animal is attacked, its family will come to its defense, circling the wounded zebra and attempting to drive off predators [2]. Struthio camelus, more commonly known as the common ostrich, is found roaming around in Africa. The ostrich is the world's largest flightless bird that also travels in small herds that typically contain less than a dozen birds [3]. Ostriches have to be aware for cheetahs, lions, African wild dogs, leopards and spotted hyena. The male ostrich is a threatening opponent and will strike out at a predator, however in most cases ostriches are able to out run their pursuer [4]. Ostriches and zebras are both prepared to warn one another at a moment’s notice so they can each flee as needed.


Relationship
Mutualism is a relationship between two species of organisms in which both benefit from the association. Ostriches share a mutualistic relationship with zebras. Ostriches tag along with a herd of zebras because they have a poor sense of hearing and smell, so they take advantage of the zebras strong hearing and smell senses [5]. Ostriches have a sharp sense of sight, which zebras lack. Thus, these two species rely on each other to inform one another of any nearby dangers; together they are more successful at fleeing from predators.


Cost/Benefit Analysis:
For zebras, there seems to be no cost. Ostriches are very beneficial by providing a better of sight that zebra’s lack. Ostriches also seem to have no cost. Zebras are beneficial to the ostrich by providing a sharp sense of hearing and smell which ostriches lack. Therefore, as mentioned above, these species employ a mutualistic relationship. The ostrich and zebra both benefit by utilizing each other’s senses and protecting one another from predators.

Reference:

Wednesday, April 6, 2011

Who Says a Hoarder Doesn't Like to to Share?

Bushy-tailed Wood Rat - Neotoma cinerea (packrat)[2]

Introduction: Pseudoscorpions is a flattened, oval, brown, black or brownish-green colored arthropod with a short fang-like appendage in front of its mouth (chelicerae). The appendage has a fixed and movable finger that allows the “scorpion” to grasp items. Also, like most arachnids it has a pedipalp, which is a pincer-like claw capable of clasping and crushing prey and secreting poison from a gland (1). Unlike the common scorpion it does not possess a long tail and is unable to sting other organisms. It is a small organism that usually reaches 5 millimeters, even though one species is capable of reaching 12 millimeters (3). Pseudoscorpions have spinnerets that allow them to produce silk for the construction of nests. On average females produce three to four clutches of eggs at a given time. The female carries her eggs until the young hatch. Although the lifespan of the Pseudoscorpions is unknown, it is believed that the adult can live anywhere from six months to two years.

[7]

Description: Pseudoscorpions feed on small insects and other arthropods, such as ants and caterpillars. They are commonly found in leaf litter, rotten logs, bark, bogs, swamps, homes, and under rocks (1). Packrats, also known as the trade rat or wood rat, are common in the deserts and highlands of western U.S. and northern Mexico, and eastern U.S. and Western Canada. They are characterized by their small stature and bushy tails, piercing call, and surprisingly an attraction to shiny things. As protection from predators, they build complex nests out of twigs and incorporate cactus spines into its design (4). To bind the objects together they urinate on the nest- the sugars and other substances crystallize to fortify the materials (4). Packrats are known for their constant search for twigs, rocks, animal dung, leaves, and sticks to add to their ever-expanding nest. Hence, the term “pack-rat” used to describe a person who accumulates materials.

How do these two organisms relate? Pseudoscorpions have established mutual relationships with birds and rodents (in this case packrats) by consuming other arthropods that invade the nest. Some species are phroretic- live on beetles and large insects, where they feed on mites in return for increased motility.

[5] Cost/ Benefit Analysis: In a phoretic relationship, the transporter gains nothing, while the other organism gains motility. According to The Art of Being a Parasite the Pseudoscorpions can become a burden on the transporter if too many passengers were to climb on board the beetle (6). However, it was observed that the Pseudoscorpion lives in the nest of the rodent. The Pseudoscorpions eats packrat ectoparasites (i.e. larval and adult fleas) and finds a place of shelter from predators, namely for reproduction. The packrat in turn receives relief from fleas, which are a nuisance because they can cause changes in the behavior of the rat, weight loss, and fur loss. All of which reduce the health of the rat, making it more vulnerable to pathogens. There is no cost incurred from this association.

Works Cited

1. http://entowww.tamu.edu/fieldguide/cimg375.html

2. http://www.americanarachnology.org/gallery_pseudoscorpiones.html

3. http://www.britannica.com/EBchecked/topic/448550/pedipalp

4. http://www.crittercontrol.com/facts/animals/packrats.html

5. http://www.localpestcontrolservices.com/pest_control_blog/arizona-pest-control/rats_pack_rats_nest/

6. The Art Of Being a Parasite

7. http://www.discoverlife.org/nh/cl/GSMNP/arachnid/key/key_order.html

I need You to Survive!

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  Introduction: Fig wasps belong to the family Agaonid. These insects are closely involved with fig trees, Ficus.  Each species of fig wasps works closely with a specific type of fig tree. Figs trees are originally from the Mediterranean area, but they are grown all over the world [2], and there are multiple different varieties of figs as well. A fig tree has two types of fruit, caprifigs which are male and edible figs which are female [1]. The lifecycle of this relationship starts when a female wasp covered in pollen enters the ostiole, opening of an unripe fig, of a caprifig. While crawling through, the female usually loses her antennae and wings, so she will never escape. The female eventually reaches an area known as the syconium, which has both male and female flowers. There she lays her eggs and releases the pollen that she brought from her original fig and then she dies [3]. While the figs are ripening the male eggs hatch first and find the female eggs and fertilize them. Then the male eggs start chewing a hole in the fig to make an escape route for the females. Later the female wasps hatch and cover themselves in pollen. Once they have enough pollen they fly through the hole in search of another fig tree. And thus the cycle continues [4]. If a female wasp enters a female fig she eventually dies, but her death is not in vain because the pollen that she brings fertilizes the fruit, and creates the fruit people/animals eat[1].



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  Description of Relationship:  The relationship between figs and fig wasps has been occurring for the last 80 million years [1].  It is apparent that these two species coevolved over the years and have become dependent on each other in order to survive [2]. This relationship is also known as a mutualistic relationship because both the fig tree and fig wasp benefit from each other. These two species exist because the other helps with the process of reproduction. The biology of the female wasps is that they have wings and are able to fly [3]. The male wasps have no wings and are unable to fly [3].



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  Cost/Benefits Analysis:
The cost of this relationship is very minimal to the benefit. Fig trees main cost of this relationship is being dependent on the fig wasp. If the fig trees cannot get their flowers fertilized by the wasps they are unable to reproduce which is a major problem. The fig wasps main cost is sacrificing the mother wasp to the fig tree because she is unable to escape due to the loss of her antennae and wings. The benefit between this mutualistic relationship is that both species are able to reproduce through the help of the other species. Also the fig tree gives shelter to the fig wasps, and in return the fig wasps fertilize the flowers of the fig which are found within. The cost outweighs the benefit because through sacrificing the mother wasp she is able produce many more wasps that will carry on to the next generation.


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