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 Photo shows a snake mottled brown and tan, with a forked tongue sticking out of its mouth.
The brown tree snake, Boiga irregularis , is an exotic species that has caused numerous extinctions on the island of Guam since its accidental introduction in 1950. (credit: NPS)

Many introductions of aquatic species, both marine and freshwater, have occurred when ships have dumped ballast water taken on at a port of origin into waters at a destination port. Water from the port of origin is pumped into tanks on a ship empty of cargo to increase stability. The water is drawn from the ocean or estuary of the port and typically contains living organisms such as plant parts, microorganisms, eggs, larvae, or aquatic animals. The water is then pumped out before the ship takes on cargo at the destination port, which may be on a different continent. The zebra mussel was introduced to the Great Lakes from Europe prior to 1988 in ship ballast. The zebra mussels in the Great Lakes have cost the industry millions of dollars in clean up costs to maintain water intakes and other facilities. The mussels have also altered the ecology of the lakes dramatically. They threaten native mollusk populations, but have also benefited some species, such as smallmouth bass. The mussels are filter feeders and have dramatically improved water clarity, which in turn has allowed aquatic plants to grow along shorelines, providing shelter for young fish where it did not exist before. The European green crab, Carcinus maenas , was introduced to San Francisco Bay in the late 1990s, likely in ship ballast water, and has spread north along the coast to Washington. The crabs have been found to dramatically reduce the abundance of native clams and crabs with resulting increases in the prey of native crabs.

Invading exotic species can also be disease organisms. It now appears that the global decline in amphibian species recognized in the 1990s is, in some part, caused by the fungus Batrachochytrium dendrobatidis , which causes the disease chytridiomycosis    ( [link] ). There is evidence that the fungus is native to Africa and may have been spread throughout the world by transport of a commonly used laboratory and pet species: the African clawed frog, Xenopus laevis . It may well be that biologists themselves are responsible for spreading this disease worldwide. The North American bullfrog, Rana catesbeiana , which has also been widely introduced as a food animal but which easily escapes captivity, survives most infections of B. dendrobatidis and can act as a reservoir for the disease.

 Photo shows a dead frog laying upside-down on a rock. The frog has bright red lesions on its hind quarters.
This Limosa harlequin frog ( Atelopus limosus ), an endangered species from Panama, died from a fungal disease called chytridiomycosis. The red lesions are symptomatic of the disease. (credit: Brian Gratwicke)

Early evidence suggests that another fungal pathogen, Geomyces destructans , introduced from Europe is responsible for white-nose syndrome    , which infects cave-hibernating bats in eastern North America and has spread from a point of origin in western New York State ( [link] ). The disease has decimated bat populations and threatens extinction of species already listed as endangered: the Indiana bat, Myotis sodalis , and potentially the Virginia big-eared bat, Corynorhinus townsendii virginianus . How the fungus was introduced is unknown, but one logical presumption would be that recreational cavers unintentionally brought the fungus on clothes or equipment from Europe.

Questions & Answers

What is randomization
Joseph Reply
definition of stimulus
Thomas Reply
please explain me clinical studies
abril Reply
clinical studies are people who evaluate behavior, medical, and surgical intervention
Connie
clinical studies are people who evaluate behavior, medical, and surgical intervention
Connie
what are the characteristics of learning?
steve Reply
The ability to learn is one of the most outstanding human characteristics. Learning occurs continuously throughout a person’s lifetime. To understand how people learn, it is necessary to understand what happens to the individual during the process. In spite of numerous theories and contrasting views
MUBARAK
Psychologists generally agree there are many characteristics of learning.
MUBARAK
Learning is the process by which one acquires, ingests, and stores or accepts information. The main characteristic of learning that; it is a process of obtaining knowledge to change human behavior through interaction, practice, and experience.
MUBARAK
Our experiences with learned information compose our bodies of knowledge.
MUBARAK
Is there not one universal understanding or relatable emotion whether physical or communicated verbally they could Trigger empathy?
Tory
what is immune system
Amanda Reply
a complex network of cells that protects the body against infection
Stephen
Sorry. Cells and proteins
Stephen
what is perspectives
acholonu Reply
someones point of view the way ur brain sees the way situations unfold
Echo
perspective is your view on topics
Trish
Perspective is your opinion on certain situations
Connie
your perspective is your interpretation of what is being said and done around you and how you hear and view them .
Jim
is this in reference to any particular use of the word? Because there are also the 7 major "perspectives" in psychology: psychodynamic, cognitive, behavioral, biological, cross-cultural, evolutionary, & humanistic
Alex
aren't they like schemas of the world, the future and yourself
naina
Perspective is your opinion on things that you feel, think or hear.
hiba
I'm trying to write a paper about video game and violence and suggestions or researches would help with this
rebal
do you also have to write about aggression and how its linked to video games and violence
naina
because for alevel psychology we could have a 16 marker essay for how media influences aggression which basically includes video games and violence on tv shows
naina
yes basically I'm arguing that video games cause violence not necessarily in a direct way but it plays apart. I'm trying to oppose the popular opinion of video games doesn't cause violence
rebal
It's not connected that much actually tbh
Kira
the way we think
according to my textbook rebal
naina
there is a lab study by Craig an Anderson- computer games mortal combat
naina
Matt delisi et al did a correlation study
naina
Lindsay Robertson et al - longitudinal study
naina
Craig Anderson also did a meta analysis of 136 studies
naina
I will check them thanks naina
rebal
Yes, that would be my recommendation.
Ashley Reply
merits and demerits of observation as a method of studying human behavior in education psychology
Khadija Reply
what is psychology
Khadija
psychology: scientific study of behaviour and mental processes.
Ahmed
how to mind reading?
UMESH
how to face reading
UMESH
energy and thought will give mind spirit and proper exercises , flexibility and making mind readind easier
Ahmed
How to read microexpresions easier?
Edg
scope of educationnalpsycology
USMAN
seriously i will pay someone to do an essay for me my god i need help so much 😪😪😪
dearbhlagh
what do you need help with ?
Keiko
The better question is how much?
Pixeled
🥒🍑😩💦
Jacob
hey all I'm Beth I just started psych 101 have 1st test any suggestions I should memorize ?
Bethany Reply
memorize dememorizing
devesh
how the blinds person his dream
Ahmed
Hi! I started as well
La
what is prototype
Arnav Reply
what is event schema
Arnav
Event schema is how you deal with situations is this installation is good you gonna handle a great but if it's badd you have to be strong I handle it the best way you can and stay positive
Connie
why do we adapt to negative events more quickly as compared to the positive ones?
Fareha
The negative ones are easier to adapt because of the people the we surround ourselves with if we surround ourselves with negative people who go to see things negatively but if we surround ourselves with positive people we are going to see things more positive
Connie
oh ok thanks!
Fareha
your welcome
Connie
what are the remedy for ADHD
anagha Reply
methylphenidate
Maryjade
counter conditioning
gad Reply
it is d conditioning were u add an unpleasant stimulus ad a pleasant stimulus to give a good response. eg a girl that hate or fears snake u add her mom to d picture because she loves her mother she gradually tends to like snake
dalusi
can I get an update on the discussion at hand
Segun
I'd like one as well, please
Trish
I third this.
Redacted
you guys could refer to a research by Mary Cover Jones. she did a study on counter conditioning.
Shubhra
i too would like to get an update on the dicussion please
Connie
so basically we are discussing about counter conditioning. if you all know about classical conditioning which was done by pavlov, later a similar thing was done by JB Watson, but on a child. this child was made to learn a phobia.
Shubhra
after his unethical experiment, his student mary cover jones also did an experiment where she proved, if a fear can be learnt, it can also be unlearn. hence, counter conditioning. where a negative stimulus (any fearful object) is followed by a pleasant stimulus (eg food).
Shubhra
After several pairings, the fear is neutralized.
Shubhra
hey, i wanted to know in positive counter conditioning a several trials are done to make the person unlearn their phobias but in aversive (-ve) counter conditioning,after just 1 trial a person learns that behaviour, why the negative behaviour is learnt in just 1 try?
Fareha
Please what is randomization?
Joseph
hi, may I have many MCQ?
Ango Reply
hi
Teri
what would you like to know
Connie
We want to know everything
victor
what's MCQ?
Ronah
Multiple Chouce Questiom
Connie
Who knows something about Multiple Personality Disorder ?
victor
Victor what you want to know in it
Brindhu
Everything you know about it.
victor
what you know about functionalism
Teri
@ Victor. Dissociative identity disorder or multiple personality disorder has two or more distinct personality states.they may be disconnected among thoughts, identity, consciousness and memory .this could be happened when to trauma of childhood incident or any other impact in life
Brindhu
how do you identify these altars ? and how do you easily identify MPD patient ?
victor
what is experimental bias
Teri
experimental bias is when you experiment with something and you like it and tell someone else about it and you tell them ira good even though they don't have the same reacton to it that you did
Connie
define Experiment
Teri
Experiment is trying something new you don't know how it's gonna work out or even if it will work or if it won't so you try it anyway it's sometimes it works and sometimes it doesn't
Connie
what is the difference between CBT and REBT
Zeeshan Reply
what it means to survive danger
Bonsa Reply
it's called bystander effect when people reject you
Jason
hey Jason
Bonsa
There are 2 meanings of surviving danger one is to be stronger than you were when you went in and the 2nd is a to have your wits about you and to keep yourself from getting into danger in the 1st place but if you have to be in danger Use your best common knowledge to get out of it
Connie
how do I overcome my fears of public speaking
Bonsa
There's many theories to that as well many people say the picture the audience in their underwear but that does not always work so what I do is I forget about the people in the audience and pretend like I'm by myself and you gonna find yourself about more comfortable and a lot more at ease
Connie
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Source:  OpenStax, Concepts of biology univ. of west georgia. OpenStax CNX. Jan 03, 2014 Download for free at http://legacy.cnx.org/content/col11612/1.1
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