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An Animal That Lives Without Oxygen
Julie188 writes "Scientists have found the first multicellular animals that apparently live entirely without oxygen. The creatures reside deep in one of the harshest environments on earth: the Mediterranean Ocean's L'Atalante basin, which contains salt brine so dense that it doesn't mix with the oxygen-containing waters above."
There is no Mediterranean Ocean. There is however a Mediterranean Sea.
There are other articles with more coverage -- Live Science, BMC Biology (PDF of 20-page article with pictures available), New Scientist, Nature, and others. The provisional PDF available at BMC Biology is the full article as it was accepted, and details the experimental procedure that confirmed that these were completely anaerobic organisms.
The summary discusses an article which is talking about an abstract of the provisional paper available at http://www.biomedcentral.com/content/pdf/1741-7007-8-30.pdf .
This probably does not answer your questions, but it covers a bit more details than the original post. Also, if you click on the title, you will link to the source article.
http://thedragonstales.blogspot.com/2010/04/anaerobic-metazoans.html
I like my dinosaurs feathery, and my pterosaurs hairy (or is it pycnofibery?)
The thing is that multicellular organisms require a lot more energy than unicellular organisms and for that there's the citric acid cycle. However there's no citric acid cycle without oxygen. This is the reason we haven't found any multicellular anoxiphiles (?) so far. I think. BTW there's a horrible mistake on the second sentence of the original article and they say it went thru peer-review. WTF! Hint: google "anoxia tolerance"
"Although a few metazoans can survive temporarily in the absence of oxygen, it is believed that multi-cellular organisms cannot spend their entire life cycle without free oxygen."
I did Google for a bit, and couldn't find anything to disagree with this, except the word 'temporarily'. While I'm not particularly familiar with anoxia tolerance, my quick searching suggests that certain species of turtle can have up to 3months without oxygen in cold water. There may be others out there, but this is the largest number I found. This is clearly a temporary phase in the life cycle of the organism. Are you trying to argue that they are implying that this is more than merely 'temporary' but a major chunk of the life cycle? Personally, were I reviewing the paper, I'd not have had a problem with allowing that phrase to be used (with the caveat that there is no information that I am not privy to currently, and there is no controversy in this area currently).
Ultimately, these animals are still dependent on a source of energy such as a sun. These animals are not capable of capturing such energy themselves, but rely on photosynthetic organisms such as plants or algae at the bottom of the food chain. As another poster pointed out, carbon dioxide is necessary for this photosynthesis, not oxygen. This is converted into sugar, which animals subsequently consume. Hydrogenosomes function similarly to mitochondria in converting sugar into ATP (more accessible energy), but differ in that they produce (surprise, surprise) hydrogen as a byproduct.
/literal reply to joke
You might think this is the case, that being bisexual 'automatically' doubled ones dating pool, but thats really not the case. As a bi male myself, I have found a significant number of heterosexual females and a notable number of homosexual males to be less than open to a bisexual partner, at least in terms of a serious relationship. Most of what I HAVE found has been more interested in open relationships or the possibility of a threesome, or something to that effect... and threesomes really aren't all they're cracked up to be, for the record.
As far as the serious relationship bit, I've never really gotten a clear answer why. Being bisexual has its own stigmas; a surprising number of people believe someone who is bisexual is actually homosexual but in denial- but really, if I was denying my interest in other guys, why would I still pursue said interest? Straight girls, in particular, seem to be somewhat averse to a serious relationship with a bi guy. I imagine it has to do with a general lack of trust, and the idea that I'd be twice as likely to cheat given twice as many potential partners, but as I mentioned that really isn't the case.
I'd say, all in all, being bisexual gives you better chances of hooking up, but makes finding a meaningful relationship more difficult overall, but your mileage may vary.
Actually, plant life needs oxygen. Plants respire just like most other multicellular organisms. They just also happen to produce oxygen through photosynthesis as a byproduct of their food production.
There is a link to the PDF of the whole article if you click on the word "published" in the mini-article.