Scientists raise air-breathing fish on land to test evolution

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in science on (#2SGP)
story imageAmong the more interesting aquatic species on our earth is Polypterus senegalus ("Bichir"), a modern African fish that has lungs for breathing air, and stubby fins. It can use the to pull itself along on land for short periods of time. That makes it an good candidate for research into previously unknown aspects of evolution. So scientists have raised a bunch of them out of water for eight months to better understand how ancient creatures may have transitioned to life on land. Have a look here for a picture of the species.1
"The researchers discovered the bichir raised on land were dramatically different than those raised in water. The land-raised fish lifted their heads higher, held their fins closer to their bodies, took faster steps and undulated their tails less frequently and had fins that slipped less often than bichir raised in water. These land-based fish also underwent changes in their skeletons and musculature that likely paved the way for their changes in behavior."
The Bichir is a pretty interesting fish. From Wikipedia, "Bichirs possess paired lungs which connect to the esophagus via a glottis. They are obligate air-breathers, requiring access to surface air to breathe in poorly oxygenated water. Their lungs are highly vascularized to facilitate gas exchange. Deoxygenated arterial blood is brought to the lungs by paired pulmonary arteries, which branch from the fourth efferent branchial arteries (artery from the fourth gill arch), and oxygenated blood leaves the lungs in pulmonary veins. Unlike most lungfish and tetrapods, their lungs are smooth sacs instead of alveolated tissue. Bichirs are unique in that they breathe using a recoil aspiration."

1 So, a bichir is worth a thousand words? Sorry.
[2014-09-17 17:54: Typo fixed: bichir, not bichr. And definitely not bitcher.]
Reply 12 comments

the Verge (Score: 2, Informative)

by zafiro17@pipedot.org on 2014-09-17 12:25 (#2SGQ)

Just noticed the Verge covered this too, and very well. There are some great quotes from that article.

http://www.theverge.com/2014/8/27/6074855/this-is-what-happens-when-you-raise-fish-to-walk-on-land
As it turns out, growing up on land really does change how a fish walks.

"Fish raised on land walk with a more effective gait," Standen says. "They plant their legs closer to the body's midline, they lift their heads higher, and they slip less during that walking cycle." The fish raised on land were also generally more consistent in the way they walked than their aquatic counterparts. But their behavior wasn't the only thing that changed. For example, "the bones in the pectoral girdle - the bones that support the fins - changed their shape," she says. "And their clavicles became elongated." Most changes that occurred were ones that gave their heads and fins more room to move around.

"It's an important change, because if you think of a terrestrial lifestyle," Standen explains, "you actually need a neck on land because you're stuck on this plane, and you need to have more head motion that's independent from the body."

Re: the Verge (Score: 0)

by Anonymous Coward on 2014-09-21 03:41 (#2SP9)

I had a wtf moment when i discovered i was on a site entitled Christian Science Monitor, thanks for linking to somewhere a little more reputable, or at least less unsettling. Does christianity come up regularly around here, i imagine an article like this would have been crucified back on /.

Re: the Verge (Score: 1)

by evilviper@pipedot.org on 2014-09-21 03:59 (#2SPA)

Condemning a person or organization for identifying as Christian, is just as bad as condemning them for identify as atheist... CSMonitor is actually one of the most reputable sources of news out there.

Here are some +5 comments about CSMonitor on /.

http://science.slashdot.org/comments.pl?sid=4075989&cid=44533929

http://science.slashdot.org/comments.pl?sid=4075989&cid=44533281

http://science.slashdot.org/comments.pl?sid=4075989&cid=44533567

http://slashdot.org/comments.pl?sid=188407&cid=15530463

http://slashdot.org/comments.pl?sid=188407&cid=15530813

Re: the Verge (Score: 0)

by Anonymous Coward on 2014-09-21 05:09 (#2SPC)

These posts all appear to be in response to various crucifixions, so i'm not sure i was far wrong. Yes, of course dismissing a christian for being christian is just as, erm, well, almost as bad as dismissing an atheist for... wait, no, christianity requires an unquestioning belief in mythical beings, that's not a great baseline for a scientific mindset, sorry. That's not to say that christians can't be perfectly good scientists, but a certain mistrust until they've proven themselves isn't actually entirely unreasonable, i tend to be sceptical about untested things(and not in a "well you can't test the big bang /theory/" way).
The thing that tipped me off, to the fact that it was a christian publication was some nonsense related to cheerleaders praying and a quiz inviting me to discover whether i'm smarter than an atheist, great stuff, guys.

In the interests of openness, i'm an atheist, are any of the pipedot staff committed christians?

Re: the Verge (Score: 1)

by evilviper@pipedot.org on 2014-09-21 05:26 (#2SPD)

I'm not aware of any religion which requires "unquestioning belief". It's common for the religious to examine their beliefs, and sometimes to struggle with faith.

I guess we could say atheism requires an unhealthy excess of skepticism, ego and self-confidence, and a complete lack of humility.

That's not to say that atheists can't be perfectly good scientists, but a certain mistrust until they've proven themselves isn't actually entirely unreasonable.

Re: the Verge (Score: 0)

by Anonymous Coward on 2014-09-21 05:44 (#2SPE)

Hmm, i get the impression that you may have something against people who identify as atheist, that's unfortunate, and not terribly christian of you, but i'll forgive you.

Faith in the existence of a god is key to christianity, the fact that there is no evidence to base one's belief in god upon, makes it an odd belief to hold, for a rational human being. Of course humans aren't rational, and religion is probably a great coping strategy for keeping a self-aware ape sane, but that doesn't mean we have to accept it as a positive influence on science reporting.

Remember, guys, don't feed the trolls.

Re: the Verge (Score: 1)

by evilviper@pipedot.org on 2014-09-22 03:13 (#2SQM)

No, I "have something against people who" are prejudiced, self-righteous and feel the need to lob insults at others. It only just happens to be coming from an atheist this time around.

Spelling (Score: 1)

by genx@pipedot.org on 2014-09-17 15:42 (#2SH8)

Bichr or bichir?

Re: Spelling (Score: 1)

by zafiro17@pipedot.org on 2014-09-17 17:53 (#2SH9)

Fixed! And yet another pipedot story whose only comment involves a spelling correction. Yay us!

Re: Spelling (Score: 1)

by genx@pipedot.org on 2014-09-17 18:54 (#2SHA)

Not sure this counts as another spelling comment, but: hit harder, there is still a living bichr :-)

Re: Spelling (Score: 1, Funny)

by Anonymous Coward on 2014-09-18 09:38 (#2SJ6)

I know. I wish she would move out.. but she owns the place.