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Here's a little bit I wrote up on them last year...(a bit dated by the holiday theme) |
5. Prionocidaris hawaiiensis. Another urchin about which we know very little... |
Except that we know where they occur in 92-214 meters? They are VERY abundant! |
6. Histocidaris variabilis. What's weird with this one? It has BARNACLES that grow on the spines!! Similar in some ways to the way that Chondrocidaris has sponges and etc. on the spines... |
7. Acanthocidaris hastigera. Not much known about this one..but dang, its cool-looking ain't it? |
8. Caenopedina pulchella These are neat because the coloration on the spines is actually EMBEDDED in the spine calcite. So, even the preserved ones are red and green! |
9. Phrissocystis multispina This is one of the weirder ones... This is a spatangoid urchin (i.e., a sea biscuit) and the group is known primarily from the fossil record. |
But the living ones are VERY fragile. I've held dry specimens..and the sediment in the gut can literally cause the bottom of these to fall out from under them. |
Thanks to Craig Young, Kevin Ecklebarger and J.L. Cameron we also know a little about its very strange-looking sperm and reproductive biology. |
Seeya guys next week! |
Tuesday, August 3, 2010 |
Cloning As Sand Dollar DEFENSE! Why run & hide when you can divide? |
Today, a little somethin' somethin' about a familiar animal..but not quite the way, you're used to thinking about it.. Today's post is based on a new, interesting paper by Dawn Vaughn who is one of the many smart people at Friday Harbor LaboratoriesThis paper was in issue 157 of Marine Biology of this year (click here!). |
Our subject is the familiar sea urchin-the Pacific Sand Dollar, Dendraster excentricus! Here is a good intro page. You can see pictures of the animal alive above..but here is how most people are accustomed to discovering it..Dendraster is a sea urchin-admittedly a very WEIRD sea urchin. and like all sea urchins (and indeed all echinoderms), the adult forms grow from a small larval stage that is so tiny, this asterisk * is probably slightly larger. |
A sea urchin larvae is called a pluteus (plural-plutei)..specifically an echinopluteus (for sea urchins). |
(Image borrowed from the Cephalopodiatrist!) |
This larval stage floats in the sea before settling down and makes up part of the plankton. So, it was discovered some years ago, that these larvae can be in the water column for quite a LONG time. Months, possibly years. This can be important in the development of the adult..as we'll see.. |
These can often be food for other creatures that live in the ecosystem at about the same time.. Often, the larvae that float become FOOD for other organisms, such as crustaceans and fish. |
Recently though, larval life has been thought of as kind of an added "secret" life and are capable of doing much more then simply floating around, waiting to be eaten or becoming adults. |
(Image borrowed from the Cephalopodiatrist!) |
It turns out that SOME echinoderm larvae, sea stars and sea urchins (probably others) can actually CLONE themselves. That is to say, they can "reproduce" asexually when they are larvae. (Adult sand dollars cannot divide in half and clone themselves in the same way..) |
But WHAT would the evolutionary significance of this action/behavior be??? How does it help the animal survive? |
In some studies, echinoderm larvae clone themselves when times are good. Food is prime and temperature is ideal. |
But what happens we investigate cloning in the context of hostile or high-risk environments??? |
There are obvious advantages to being able to clone oneself in the face of danger from predators, such as safety in numbers and so on. |
To investigate these questions Vaughn set up an interesting experiment. |
They cultured the plutei from Dendraster excentricus and cleverly created an experiment that simulated the presence of different, local fish species in the environment! How did they do that? They isolated and concentrated the fish MUCUS from 2 different species-the stickleback (above) and Dover sole (Microstomus pacificus). |
One of the groups was a "control" group-i.e., fish were not encouraged to attack, whereas the other group had mucus introduced as the "hostile" environmental factor. |
Vaughn identified the presence of cloned Dendraster based on the the increased density of larvae (these were in a closed area after all) and the presence of larvae showing physical traces of budding. So, indirect and direct ways of determining the presence of "Uncloned" versus "Cloned" |
Here's what they got... |
(Figure 2 from Vaughn, 2010) |
Vaughn found that all of the larvae left in the control (without fish mucus to "threaten" them) were much fewer and much LARGER. Mucus-treated larvae INCREASED in numbers and DECREASED in SIZE over the duration of the experiment. |
Figure 2 above shows a nice scale comparison of plutei from the Uncloned versus Cloned subjects. |
Take-Away Message #1: When threatened, Dendraster larvae are apparently ENCOURAGED to clone themselves more! Cloned Dendraster are smaller. |
Vaughn also performed trials where they looked at direct effect that fish attacks would have on the larvae. |
On the graph below, the black bars represent UNCLONED larvae eaten whereas the grey bars represent CLONED larvae eaten. |
(Figure 5 from Vaughn, 2010) |
The UNCLONED (and LARGER) larvae (in black) suffered substantially GREATER losses to attacking fish then those CLONED (and SMALLER) larvae (in grey). |
So, the rather strongly suggests that being able to clone oneself (thus creating MORE and SMALLER) individuals is an adaptive defense. (I suppose that's kind of a bummer if you're one of those larger larvae that get eaten though!) |
Bear in mind the time scales here also... The asexual cloning doesn't work on an individual-individual instant scale..i.e., fish approaches and larvae splits. But when the fish leaves a mucous presence in the area..it presumably sets all of the larvae on alert to begin cloning themselves. |
This can have a potentially important evolutionary and ecological effect. The presence of more larvae suggests that more fish could be present. Is escalation present? What is the effect of having these cloned larvae on the variation and evolution of the adults? |
Twitter: Good or Bad? |
twitter, good, bad, follow me, influence |
Twitter has already passed Facebook on the ladder of social networking, but is the site good or bad for society? It has been hard to escape the phenomenon and it has left people with yet another social media compulsion that needs to be watered daily. |
Twitter allows us to “create and share ideas and information instantly without barriers.” The team has certainly perfected their slogan to entice us, with emphasis on the no barriers, which is the exact thing that gets you trapped within its digital walls. It makes it possible for us to know precicely what our favorite celebrities are doing and where they are through their personalized tweets. This is the first time in history that you can stalk the famous without being arrested for it. You can also connect to your friends, but who wants to do that when you can be linked to the likes of Justin Bieber and Demi Lovato? |
You can log into Twitter through your mobile, so you can stay connected wherever you are. This is a good thing for those needing their hourly update, but a bad thing for those who start to sweat when they have no signal and feel they have lost connection with the world, or more correctly, Justin Bieber. |
This new revolution of getting to know your favorite star on a personal basis and following their exact movement, has led many people, especially the younger generations, to be infatuated with Twitter. |
This ability has also led to serious crime, which makes us question whether Twitter is good or bad? The notorious “bling ring” gang used twitter to burglarize the homes of Hollywood celebrities. It helped them to track when their targets would be out, such as Paris Hilton and Orlando Bloom. Google Earth then provided the tools they needed in order to work their way into the mansions and the thieves came away with more than $3 million. The story has now also been made into a movie, so as you can see, Twitter produces money for people in more ways than one. |
It is a magnet for millions of users. It makes money by selling advertisements and is predicted to gain $600 million in sales this year. However, for the amount of users it has, this is not seen as such a great achievement. |
User growth continues and was up by 6 percent in the latest quarter. 230 million people have accounts and the person holding reign for the most Twitter followers is Katy Perry, followed by – Justin Bieber, Lady Gaga, Barack Obama, Taylor Swift, Britney Spears, Rihanna and Justin Timberlake. As you can see, Barack Obama is the only political presence in the list, despite other political figures having a Twitter account for people to follow. However, at least we can wipe our brows that Obama received the tweeted nod. |
This acts as proof, that Twitter is mainly used by people to follow their favorite celebrities. It has become a universal obsession and it has even led to crime. So, are social media networks like twitter a good or bad contribution to the daily lives of society? It merely seems to be a way for people to make money, and invade the privacy that other people should want to keep private. |
By Melissa McDonald |
Wednesday, October 15, 2014 |
Who's really to blame? |
And, yes, I'm speaking from experience here. |
Now just grow a pair and say it. |
Monday, December 9, 2013 |
Trust is a scary, scary word. |
In just 5 simple letters, an entire lifetime can be completely ruined. |
How are you supposed to trust someone completely? Entirely? Forever? |
I ask this question simply because I do not know the answer. |
Love baffles me, but I still believe in it. I love my mom. I love my major. I love my boyfriend. |
But how do I know that I can trust them? Are love and trust actually meant to go hand-in-hand? I'm not sure. |
I do know that love requires some level of trust, but how high does it have to go? Should it be just enough or enough to fill the oceans? |
I trust my boyfriend with my life, with my heart. But when he goes out, I get nervous. I'm afraid of things that will probably never happen. I'm afraid of losing him again. I'm so afraid of something that I can't even put a name to. He, however, thinks I don't trust him. |
Is that what trust is? Having no fear of something bad happening to the one you love? Is trust letting go of all your worries and all your cares? See, that's where I think his definition of trust is wrong. |
Do I think my boyfriend is going to cheat on me? No. |
Is the opportunity presenting itself to him? Maybe. |
Does that make me nervous? Yes. |
I don't think that trust has anything to do with being nervous about your loved ones. |
Trust is simply giving someone the chance to hold your heart. Trust is the action of loving. Trust is knowing that at any moment, they could tear your world apart, but you still give them your world anyway. |
That's my definition of trust. What's yours? |
Wednesday, March 6, 2013 |
Courage or Crazy? |
I have always believed that you should have the courage to say exactly what you feel and not have any regrets. You feel what you feel, and people have a right to know how you feel about them. I know that I would want to know! So, I've made it a point the past couple weeks to tell people exactly how I feel about them. |
Unfortunately, I've only had the chance to do so one time. I told one friend of mine that I'd had a crush on him for a while and thought that we would make a great couple someday. And, much to my surprise, he agreed! And admitted that he'd been crushing on me, too! Nothing is going to come of it, at least not yet, because he is abroad right now and we will both be going to different schools in the fall. But, it was nice to know that I had an admirer. |
To be able to buck up and say how I feel was liberating. Maybe I only feel so confident about it because I haven't had any negative feedback yet, but I'm sure it's equally as liberating when the person doesn't appreciate it. |
So, to wrap up this extremely short blog, say how you feel! Compile all the courage you can and just blurt it out. Say it to their face or send them a text! (Just be sure to hit send before you change your mind). |
Wednesday, February 27, 2013 |
Prince Charming My Ass |
It's been too long since I've written! Let me give you all a little catch up story. |
First of all, remember Prince Charming? Well, it was too good to be true. He was more like Prince Cheater. With people that I go to school with, and I go to a school with about 1,000 students. Needless to say, we figured it out real quick. So, my views on love, anyway, have changed just a little since my last post. |
But, you can never lose hope. I still think that my Prince Charming is out there somewhere. And he won't be a Prince Cheater, a Prince Liar, a Prince Mistreater, or any of those things. He will be the right one for me and I'll be the right one for him. |
That being said, I have realized a few things since this whole fiasco has gone down. |
1. People aren't always who they make out to be. |
2. Trust your gut, it's probably right. |
3. Listen to your mom, she knows what she's talking about. |
4. When you say no more chances, mean it. |
All I'm trying to say here is that we, as women, deserve to be treated like a princess. I mean, why else would we refer to our perfect man as Prince Charming? I've never heard any man call his perfect woman Princess Perfect or anything along those lines. Sure, girls are dreamers and we can get our heads stuck up in the clouds sometimes (or, rather, up the asses of our current boyfriend). We still deserve to be treated how we wish to be treated. We are all princesses, and, dammit, we deserve our freaking prince. |
So ladies, if you've found Prince Charming hold on to him tight. In fact, you should probably tie him up somewhere so he doesn't run off to find like three more Cinderellas. Don't let his words fool you, judge him by his actions. And never, I mean never, give someone a second chance. If they couldn't do it right the first time, they sure as hell aren't gonna get it right the second... or third... or fourth. |
Keep your heads up high so your tiaras never fall off. |
Love always, |
Tuesday, November 6, 2012 |
Essential Maintenance Tips for your Computer |
by: Software bazar |
The computer is one of the most important inventions to have taken place in the 20th century, which has grown over several decades contributing to the growth and changes in human learning and behavior. Today the computer is an essential part of human life without which they cannot do their day-to-day tasks. |
This amazing machine has made life easier for most people and contributed to their overall growth. Today almost all household have at least one computer but the most important question that arises here is, if the owner is concerned about the proper maintenance of the machine or not. |
Most people either fail or forget to properly maintain their computer from both internal and external threats that can seriously jeopardize the functioning of the machine. However, with just a few important tips you can effectively maintain your computer and can keep its functioning as good as ever. |
Here are a few essential maintenance tips to keep your computer stable and in a perfect condition: |
1. Perform a disk clean up for maintaining the speed of your computer. Running regular disk clean up can clean your system of unnecessary data. This step can be done manually or by running the disk cleanup utility in Windows. |
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