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This week was a bit difficult in trying to identify the unknown organism.  It looked like some kind of insect but it was hard to tell.  First we identified it into its supper family Coccoida, then once we identified that it seemed fairly easy to identify the organism to species.  Turns out the unknown organism was a Cottony Cushion scale.   Which belongs to the order Hemiptera, and the suborder Sternorrhyncha.

In Hemipterans the mouth, or “beak”, is modified mandibles and maxillae to form a “stylet”.  Sternorrhyncha refers to the location of their mouth which is towards the rear of the head of the organism.  When the organisms are not feeding the mouth is usually folded up and under the body.  Hemipterans are typically parasites that feed on plant sap.   In order to ingest the sap the mouth is built up of two channels.  One to let liquid food in and the other to pump their saliva into the food source.  To help this process they inject enzymes which are in their saliva to begin digestion before it is ingested.

Hemipterans have wings to help them move more efficiently.  Their wings are either entirely membranous in Sternorrhyncha and Auchenorrhyncha.  Heteropera have partially hardened forewings that are hardened towards the base and membranous at the ends.  Hemiptera has a Greek origin meaning “half wings”, “hemi” meaning half and “pteron” meaning wing.  Though these wings are to help with locomotion, they are used for short distances and not for an extended period of time.

Since Hemipterans are insects and insects are found all around the world and there is an abundance of orders to try and compare and contrast this week, I will just be discussing some of the major adaptations and different features of insects to help them survive in different types of environments.

To start off the exoskeleton of insects is a major feature that helps them survive in any habitat.  It gives structure to the organism and it also acts as a shell to help protect them from predators.  It also helps with the loss of fluids in arid and fresh water environments.  It also is a advantage to the muscles to help with agility and strength in locomotion.

Another great advantage for insects is there size. Such majority of them are fairly small organisms it makes it easier for them to hide from predators.  Also If the organisms were larger it would require a lot more energy use from the organism. It would have a larger exoskeleton which would require more muscles mass to move the extra weight from the exoskeleton and the rest of the organism.  With their small size they do not need as much resources as compared to a human, just based off of the size difference.  A drop of water can quench their thirst and one plant could feed an organism for its whole life span. (depending on the organism, not true for all insects)

The ability of flight is a huge beneficial factor in insect survival.  It allows a quick escape from predators, and it also allows for populations to expand more quickly.  They can find resources faster by covering more ground.

Insects have a closed digestive system.  Within the digestive system there is the alimentary canal that runs length wise through the body connecting the mouth and the anus.  This canal processes the food as it travels through their body.  There are three different sections of the digestive system that allow for enzyme production, grinding of food particles, nutrient absorption, and food storage. The three sections are the foregut, midgut, and hindgut.  The stomatodeum (foregut) is the region that grinds and stores food.  Mesenteron (midgut) is where the digestive enzymes are produced and secreted, also this is where the nutrients are absorbed.  The proctodeum (hindgut) divided up into three sections, the ileum, colon, and the rectum.  This is where water, slats and other substances are absorbed before excretion.

Diagram showing the foregut, midgut, and hindgut and where they are located in the body.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiO-KTwjufXAhUF7YMKHcLfCNEQjRwIBw&url=https%3A%2F%2Fwiki.bugwood.org%2FInsect_Biology&psig=AOvVaw31MC6U7SnQckVcLGU7dl1h&ust=1512159370047994

 

 

Insects have a circulatory system.  The main function for the circulatory system is to transport nutrients, hormones, and wastes throughout the insects body.  It also plays a role in helping with osmoregulation, temperature control, and immunity.  It can help in the storage of water carbohydrates and fats.  Insect blood is different than human blood in that it does not contain any red blood cells which carry oxygen.  Hemolymph (insect blood) has molecules, ions and cells. These help with regulating the chemical exchanges with in the body.

Diagram showing how insect circulatory system operates with its respectable parts for circulation.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiSl-iqj-fXAhUH_IMKHRYOB8EQjRwIBw&url=https%3A%2F%2Fwww.britannica.com%2Fanimal%2Finsect%2FCirculatory-system&psig=AOvVaw3nZKlVJC7Ynuvg70CN0xT9&ust=1512159517602325

 

Insects do have a respiratory system but they do not have lungs.  They have a system of tubes and sacs where gasses either diffuse or directly pumped to the designated area of the body.   I think this is brilliant because it pumps directly to the tissues that need it but at the same time it reduces carbon dioxide because of their cells.  The air is taken into the body by spiracles (openings) which are located on the thorax of the organism.  Insects can have from 1 to 10 spiracles depending on the organism.  Carbon dioxide is leaves the body the same way it enters the body.  There are different ways in which insects can perform gas exchange depending on the species.  Respiration can range from discontinuous gas exchange, diffusive ventilation, and continuous reparation.  Aquatic insects do not have spiracles but they do have tracheal gills.

Insects respiratory system

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEwjQjOXwj-fXAhUK3IMKHaToAQcQjRwIBw&url=https%3A%2F%2Fwww.britannica.com%2Fanimal%2Finsect%2FCirculatory-system&psig=AOvVaw0Pr-gI4TMZaFiTheL4NScv&ust=1512159634433798

To help with locomotion insects have muscles.  Unlike humans how we have smooth and striated muscles, insects only have striated muscles.  There are four muscle groups that help with certain movements of the organism.  Visceral muscles surround the tubes and ducts that help with the digestive system, for example.  Similar to our smooth muscles in us humans.  Segmental muscles that are used for molting and locomotion in larvae that have no legs.  The appendicular muscles move the legs while flight muscles do what you would expect from muscles that are called flight muscles, they help with flying.

How the muscles make the wings work

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj8va-okOfXAhVl9YMKHb6nAVkQjRwIBw&url=https%3A%2F%2Fprojects.ncsu.edu%2Fcals%2Fcourse%2Fent425%2Flibrary%2Ftutorials%2Fexternal_anatomy%2Flocomotion.html&psig=AOvVaw0KMglZMt7AfXuvKky7WKWS&ust=1512159747343872

How muscles make the legs move

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiE9P26kOfXAhVD04MKHRNrADUQjRwIBw&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AWing_Muscles%2C_color.svg&psig=AOvVaw0KMglZMt7AfXuvKky7WKWS&ust=1512159747343872

 

Insects also have an endocrine system that produces hormones that will stimulate processes that the organism needs in order to survive.  There have been four endocrine centers that have been identified that can help with multiple functions of the organism.  Neurosecretory cells are cells in the brain that produce one or more hormones that affect homeostasis, reproduction, metamorphosis and growth.  There is a pair of neuroglandular bodies called corpora cardiac located behind the brain.  These produce neurohormones and store and release other neurohormones that stimulate secretory activity of prothoracic glands which plays a role in molting.   Prothoracic glands play a role in the molting process and reproduction in females.  These glands are located either in the back of the head or the thorax.  Corpora allata, secretes juvenile hormone that regulates metamorphosis and reproduction.  These paired glandular bodies are located on either side of the foregut.

Insects have a complex, centralized nervous system.  They have a brain, a subesophageal ganglion connected to the brain, and a ventral nerve cord.  Their brains have three lobes, the protocerebrum, deutocerebrum, and tritocerebrum.  Protocerebrum that is connected to the compound eyes and ocelli.  Deutocerebrum are connected to the antennae and the tritocerebrum connected to the oregut and the labrum.  Insects have multiple sensory organs.  They have chemoreceptors that for taste and smell.  Mechanical sensors such as the little hairs that are sensitive to touch, pressure and even sound.  Even though those hairs can be sensitive to sound insects can also have hearing structures.  They can be located from the wings, antennae, abdomen, to the legs.  Insects have eyes that are very light sensitive.  They can see colors as well and even in some orders of insects they can see ultra-violet light.  Multiple insects have humidity and temperature sensors as well.  Not until recently insects were thought to not have pain receptors but recent findings say that Fruit flies may have them.  This questions, do all insects not have pain receptors.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwi_jpeAkefXAhWK5oMKHW0QCVMQjRwIBw&url=https%3A%2F%2Fwww.earthlife.net%2Finsects%2Fanatomy.html&psig=AOvVaw0UOka2Jyo1_vJnpNmd-xhD&ust=1512159964054079

All these adaptations that the insects have acquired over the years have allowed them to inhabit multiple environments.  Insects are very unique and interesting organisms.

last revised: 11/30/17

 

Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 728, 748. ISBN 978-81-315-0104-7.

Gullan, P.J.; Cranston, P.S. (2014). The Insects: An Outline of Entomology, 5th Edition. Wiley. pp. 80–81, 790–. ISBN 978-1-118-84616-2.

Nation, J. L. (2002) Insect Physiology and Biochemistry. CRC Press.

McGavin, George C (2001). Essential Entomology: An Order-by-Order Introduction. Oxford: Oxford University Press. ISBN 9780198500025.

“General Entomology – Digestive and Excretory system”. NC state University. Retrieved 2009-05-03.

Triplehorn, Charles A; Johnson, Norman F (2005). Borror and DeLong’s introduction to the study of insects. (7th ed.). Australia: Thomson, Brooks/Cole. ISBN 9780030968358.

Duncan, Carl D. (1939). A Contribution to The Biology of North American Vespine Wasps (1 ed.). Stanford: Stanford University Press. pp. 24–29.

Elzinga, Richard J. (2003). Fundamentals of entomology (6th ed.). Upper Saddle River, NJ: Prentice Hall. ISBN 9780130480309.

SCHNEIDERMAN, HOWARD A. (1960). “DISCONTINUOUS RESPIRATION IN INSECTS: ROLE OF THE SPIRACLES”. Biol. Bull. 119 (119): 494–528. JSTOR 1539265. doi:10.2307/1539265.

Eisemann, C. H.; Jorgensen, W. K.; Merritt, D. J.; Rice, M. J.; Cribb, B. W.; Webb, P. D.; Zalucki, M. P. (1984). “Do insects feel pain? — A biological view”. Experientia. 40 (2): 164. doi:10.1007/BF01963580.

Tracey, W. D.; Wilson, R. I.; Laurent, G.; Benzer, S. (2003). “Painless, a Drosophila Gene Essential for Nociception”. Cell. 113 (2): 261–273. PMID 12705873. doi:10.1016/S0092-8674(03)00272-1.

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This week I will be talking about the physiology of mollusks.  I had some trouble identifying the organism this week but luckily my partner figured it out.  The organism this week was the Eastern Emerald Elysia.  Also known as the Elysia Chlorotia.  (As seen below provided to us by our professor.)  While trying to find what phylum this organism belonged to I found a very interesting fact about this organism and that is it can partake in photosynthesis.   The organism does this by taking the chlorophyll cells from the algae that it eats and uses those cells then to photosynthesize and make its own food.  The relationship that this organism has with the algae is known as subcellular endosymbiotic relationship.  This is the only mollusk that does this.  So here is some more about the rest of mollusks.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjh3-Cd1Y_XAhXK54MKHeWVAjwQjRwIBw&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D0qY0YlbvKtw&psig=AOvVaw2VqJ99RJY1SGBgM-QD1AMS&ust=1509154518913661

There are six classes of mollusks and they are gastropods which are your snails, slugs and so on, cephalopods which are your squids and octopi,  caudofoveata, solengasters, which are worm like creatures, bivalves which are the clams and oysters and the last class is polyplacophora, chitons.  Mollusks is one of the largest phylum with around 93,000 species which majority of them classified under gastropods.   All mollusks have a few things in common.  To start off they have a coelom hat that contains organs suspended from the mesenteries.  They also have a mantle cavity where majority of their organs are located.  The exact location of the mantle cavity varies from organism to organism.  The organs that the mantle contains are reproductive organs, the gills, kidneys, and the anus which is formed of chemical sensors named osphrodia.  The mantle also secretes the shell that can be found on some mollusks.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiLmMG304_XAhWF2YMKHSjhCBYQjRwIBw&url=http%3A%2F%2Fwww.mesa.edu.au%2Fmolluscs%2Fmolluscs_01.asp&psig=AOvVaw0w2B5_Hu959Nyfl9hItRA0&ust=1509154053071348

Mollusks have feet but the functions of those feet varies between classes.  Gastropods have feet that help them move, and cephalopods can also help them move but it is either to help them swim or help them grab onto prey.  For example in limpets the foot is turned into a sucker to help anchor them to a hard surface.   Locomotion for gastropods is possible by muscular contractions in the foot.  Cephalopods have fins and use jet propulsion to help them swim quickly through the water. Caudofoveata and solengasters have spines that are called calcareous spicules. Bivalves have a muscular foot.

We have all seen a snail and seen the trail of slime that it produces.  Well turns out that the mucus is very important to these organisms.  The mucus helps with locomotion by allowing the organisms to slide along easier.  It also helps with digestion by helping carry food particles throughout the digestive tract.  I thought of this as like the saliva that we humans produce.  I also read that they can use the mucus to help them feed as well.  They will send out strings of mucus to catch stuff that is drifting by and then retract the mucus and then eat the stuff that it caught, kind of like a filter feeder.  Since we are talking about feeding, these organisms have a complete digestive and excretory system.  They have a mouth and an anus that is connected by a complex stomach.  Since these organism can use their mucus like a fishing pole per say, they have a highly developed nervous system.  I found these organisms very simple but yet complex and very fascinating I hope you did too.

SOURCES

Anatomical and Physiological Phylum Mollusca Characteristics. (n.d.). Retrieved October 26, 2017, from https://animalsake.com/phylum-mollusca-characteristics

Kennedy, J. (n.d.). What Are the Characteristics of the Gastropoda? Retrieved October 26, 2017, from https://www.thoughtco.com/class-gastropoda-profile-2291822

What is a Mollusk? (n.d.). Retrieved October 26, 2017, from http://eol.org/info/445

https://en.wikipedia.org/wiki/Mollusca#Classification

 

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This week in class we were presented a worm looking like creature that lived in the sea.  So that is what i typed into google and searched until I found something that looked very similar to the picture we were presented in class.  I found that the organism belonged to the Annelida phylum.  To double check I found characteristics of that phylum and compared it to the unknown organism.  Turns out I was correct that the organism was in the Annelida Phylum.  This week I will be discussing the Ecology of these organisms.

Annelids can be found almost anywhere on the planet, from the mountain tops to the deep blue sea.  These organisms live in marine, freshwater, and terrestrial environments.  They can even be found in other organisms (parasites).  Majority of these species of worms live in the sediment/soil of their environments.  This is where they rework the soil and sediments.  they do this by burrowing and ingesting and excreting the sediments and soils.  Most of these organism help the environment more than they harm it.  They are fantastic decomposers, and they are a part of so many organisms diets.

OLIGOCHAETA (Earthworms)

The Oligochaeta class has freshwater and terrestrial species. These organisms mainly are deposit feeders, meaning that they will eat the soil/sediment that they burrow through.  This is healthy for the environment that they live in because it puts nutrients back into the soil and they also aerate the soil.  This allows for new plant growth and healthy stronger vegetation.  They are also important in the food web as they are a food source for multiple species.

http://www.differencebetween.info/difference-between-earthworm-and-leech

 

POLYCHAETA (marine worms)

Polychaeta class are primarily made up of marine organisms that can be found free floating or burrowed into the sediment.  The ones that are free floaters are active predators and hunt for their food.  The organisms that are not active predators they are filter feeders or scavengers.  These organisms will eat the dead organic matter that floats to the bottom of the ocean floor.   Many of the organisms in this class have a commensalism  relationship with its environment.  That means that the surroundings benefit from the organism without any negative impacts on the worm or its surroundings.  There are only good things that happen in this relationship.  The worms do this by excreting what ever they eat and putting the broken down organic matter back into the soil or sediment.

http://biologyboom.com/wp-content/uploads/2014/08/3a1.jpg

HIRUDINEA (leeches)

These organisms can be found anywhere from the water to the dirt.  Hirudinea are all carnivores.  Many of these species are parasitic. Most of these organisms have a negative relationship with their prey or host.  They will either latch on and feed off of the host’s blood or they will attack and eat their entire prey.  This is not good at all for the host.  Once attached they also release a anticoagulant that plays a role in where they get their name from called hirudin.  Most species are found in freshwater, but some species can be found in the ocean or in moist soil.  Leeches are a key organism in the food web.  They are mid-level consumers, so they keep the populations of species that they eat in check and the leeches are also a food source for multiple species.

http://www.differencebetween.info/difference-between-earthworm-and-leech

 

sources

Annelida: Life History and Ecology. (n.d.). Retrieved October 06, 2017, from http://www.ucmp.berkeley.edu/annelida/annelidalh.html

Wilkin, P. D., & Blanchette, J. (2017, June 16). Annelid Ecology. Retrieved October 06, 2017, from https://www.ck12.org/biology/Annelid-Ecology/lesson/Annelid-Ecology-Advanced-BIO-ADV

Bio. (n.d.). Retrieved October 06, 2017, from https://www.emaze.com/@AFWZRTLW/Bio

https://en.wikipedia.org/wiki/Leech

http://www.biokids.umich.edu/critters/Hirudinea/

 

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This week’s unidentified organism was a little hard for me to identify.  So like usual I went to straight to google images to see if I could find something similar to the organism.  It wasn’t until the professor presented us with a picture of the organism with a measurement.  When I found a similar organism I searched the phylum of known organism (Platyhelminthes) and found some distinguishing features to the phylum.  I then compared those features to the unknown organism and all the features matched up.  So I came to the conclusion that the unknown organism had to be in the Platyhelminthes, also known as flat worms.

The features I used to determine that the unknown organism was part of the Platyhelminthes phylum are listed below.

1) Bilaterally symmetrical.

2) Body having 3 layers of tissues with organs and organelles.

3) Body contains no internal cavity.

4) Possesses a blind gut (i.e. it has a mouth but no anus)

5) Has Protonephridial excretory organs instead of an anus.

6) Has normally a nervous system of longitudinal fibres rather than a net.

7) Generally dorsoventrally flattened.

8) Reproduction mostly sexual as hermaphrodites.

9) Mostly they feed on animals and other smaller life forms.

 

Some interesting things that I found out about this organism while I was doing some research is that they have 3 layers of tissues (triploblastic).  This third layer of tissue is a connective tissue layer that serves as a storage reservoirs.  The three layers are the ectoderm, mesoderm and endoderm.  This phylum is the first group to develop a true mesoderm.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiLuYSkkOnWAhUC-J8KHdtgATsQjRwIBw&url=http%3A%2F%2Fheyerbio6a.wikia.com%2Fwiki%2FTriploblastic&psig=AOvVaw31AqxCIcppsjkmessUCG4s&ust=1507830447865999

 

Platyhelminthes have no internal cavity.  These organism have a digestive cavity only but there is no space between the gut and the body wall.  This leads me to the next interesting fact about these organisms.  These organisms have no anus, so they shit where they eat.  They use their mouths to take in food and when digestion is finished they excrete the waste out of their mouth.

These organisms do have sensory organs and nervous tissues at one end of their body giving them a head and a tail.  They do possess light sensing organs but there is not many, meaning that they do respond to light but not very well.   Since the only cavity in the organism is the gut this causes the worm to be flat.  Since they are flat the gut is branched out so that it can transport food to all the cells easily.  Also they have to be flat in order to respire by diffusion.

https://www.google.com/imgres?imgurl=https%3A%2F%2Fwww.biologycorner.com%2Fresources%2Fflatworm.gif&imgrefurl=https%3A%2F%2Fwww.biologycorner.com%2Fbio1%2Fnotes_flatworms.html&docid=mGd34ZhxES9n2M&tbnid=WfujvzUbUc6fkM%3A&vet=10ahUKEwiqpK7ZkOnWAhUI5oMKHZFVDo0QMwjxASgSMBI..i&w=502&h=380&bih=929&biw=958&q=flat%20worm&ved=0ahUKEwiqpK7ZkOnWAhUI5oMKHZFVDo0QMwjxASgSMBI&iact=mrc&uact=8

 

There are four classes in the phylum of Platyhelminthes, Turbellaria, Monogenea, Trematoda, and cestoda.  All four of these classes are very similar but yet have minor differences.  For example, most of these organism don’t have appendages.  For the class Monogenea they may have clamps, suckers, hooks and spines.  These are used to help for feeding.   Some of these features can also be found in different classes.  In turbellarians they differ based on the digestive cavity or the lack of digestive cavity.  In Trematodas most of their body cavity is taken up by their reproductive system.  With most of their body taken up by the reproductive system they can produce large number of offspring.  Cestoda have no mouth or digestive system so their food is absorbed through the cuticle.  Also their reproductive system is linearly arranged called proglottids.  All of the organism in the phylum Platyhelminthes are all very similar, having flat bodies, consisting of three tissue layers and they don’t have an anus.  They can differ as I talked about above.  These are unique and amazing organisms.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjeyIeQkenWAhVLrlQKHThDBFoQjRwIBw&url=https%3A%2F%2Fwww.slideshare.net%2Fdryuktisharma%2Fchapter-25-41857144&psig=AOvVaw367Ge8tuP3dANvQymuOE-s&ust=1507830665786062

 

Sources

“The Phylum Platyhelminthes.” The Flatworms and Tapeworms (Phylum Platyhelminthes),    www.earthlife.net/inverts/platyhelminthes.html

“Platyhelminthes.” The Columbia Encyclopedia, 6th Ed, Encyclopedia.com,     www.encyclopedia.com/plants-and-animals/animals/zoology-invertebrates/platyhelminthes.

Introduction to the Platyhelminthes, www.ucmp.berkeley.edu/platyhelminthes/platyhelminthes.html

http://www.dscc.edu/sites/default/files/bwilliams/bio%20II%20lecture_notes/Animal%20Kingdom/Survey/04%20Platyhelminthes.pdf

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