View Full Version : Question About Deep Sea Marine Life
It's my understanding that when a life form has great pressure exerted on it constantly, such as a hypothetical creature on a hypothetical planet with a hypothetically heavy gravity or high atmospheric pressure, that it will, over the course of generations, become smaller in response to that pressure. So why is it that deep sea marine life tends to be so big? Wouldn't the pressure of the depth cause smaller and smaller bodies to form? Or does a larger body form to equal the amount of pressure coming in with an amount "going out"?
(A little background on the source of the question: I had gone to the Monterey Bay Aquarium and was at their deep-sea tank. Along the floor in front of the tank were pictures of the various fish found therein, all to scale. The deep-sea sunfish was depicted as being somewhat smaller than a barracuda, oh foolish me for believing that. Several others as well as myself were looking for a much smaller fish when this thing the size of a Volkswagen Bug swam by. It was a truly awesome sight. I just couldn't figure out how something from an environment with that much pressure could get so huge.)
08-01-00, 01:28 AM
I think the greater pressure as found in the deep seas has more of an affect on the composition of the animal's body rather than on the actual body size i.e. the animals may be large, but they are soft-bodied or in many cases gelatinous. Of course, the sea in general tends to have rather large creatures in it e.g. the blue whale, the rarely seen giant squid, etc., where such large bodily masses aren't as problematic given the watery environment as they would be on land albeit terrestrial creatures of old could also get quite large e.g. "Barney" and his lot from the Mesozoic era. As for the affects of gravity on body size, well yes there is an affect. I remember hearing that cosmonauts, who have been in space for extended periods of time, actually got taller by something like an inch due to the lack of gravitational pull. The only down side was calcium leaching in the bones as well as muscle degradation. This is why one sees cosmonauts being lifted out of their capsules and carried; acclimatization takes awhile. Gee, all that trouble to be an inch taller, they could have just gotten themselves put on the rack. As a side query, is anyone familiar with any types of "deep" terrestrial creatures other than the common run of moles and earthworms?
Thank you for your answer. The question had been bugging me a little. As far as being an inch taller, I'm 5 foot 2! Every inch helps! LOL :D!
Based on the fluidity of water versus the solidity of terra, I don't think we're going to find any large subterranean creatures, and that's somewhat of a relief if you ever saw "Tremors"... :)
08-16-00, 04:48 AM
I LOVE THAT MOVIE!!!!!!!!
Okay, here's the facts:
I'm not your average computer geek or science freak.
I'm not all that great in science, especially when the use of big words come into play.
I'm UNDER 18...
While in the Science Olympiad, I stank from here to high heaven.
I do enjoy Bill Nye the Science Guy.
My favorite subject is History.
I've never divulged myself in a book about Anti-Matter.
I don't do crazy chemistry experiment in the basement (basically because we don't have one, but that besid the point).
I'm an Aries.
I love science-fiction and anime.
I've actually aced several science tests.
I've never made any scientific modifications.
The best character on Star Wars Episode 1 was JAR JAAR BINKS!
08-16-00, 03:17 PM
Just a little tidbit... At CTY (basically a geek summer camp with 3 more weeks of school) for his final project project, one of my friends did on a certain kind of fish in the marianus trench. He said that if so many psi. were put on the fish, then it would have to give off so many psi. in order to prevent getting squished by all the pressure. He then theorized that if you captured this fish at it's normal depth, put it in an equivilent pressure chamber, took it to the surface, and released the pressure, all the psi. the fish was giving off would result in the fish exploding.(phew) He then went on to what would happen if you released the fish in space suddenly. i contributed by asking about its possible future in warfare...
Questions? Comments? Concerns?
08-16-00, 04:53 PM
He is right - when fish are brought up from depths too quickly, their swim bladders rupture and sometimes their internal organs come out through the mouth. If there were a magic way to instantly transport a fish from a kilometer down to the surface (or into vacuum), it would explode. Now, did he go on to say that a fish or a person exposed to vacuum explode? If yes, he is wrong - difference between surface pressure and 1 km depth is 100 atm; difference between surface pressure and vacuum is only 1 atm. Human skin is pretty tough and can withstand this difference. The movie 2001: Space Odyssey was correct where an astronaut survived in vacuum long enough to open a hatch. As for future of warfare... if we ever have people fighting in space, loss of pressure will be a major problem. Explosive decompression won't make people explode, but it can kill them in less than 30 seconds. At the sea you have the opposite problem - submarines maintain surface pressure inside, so if the hull is breached, everyone inside is crushed as water rushes in.
Rapid ascent is a bad idea for scuba divers mostly due to danger of decompression sickness, i.e. nitrogen bubbles in the blood. Holding your breath while ascending is a VERY bad idea - your lungs CAN rupture, - but not doing that is one of the first things drilled into students in the beginner scuba course.
08-16-00, 11:37 PM
I forget who it was that once told me that submarines doing rapid ascents would occasionally "pop" a few denizens from the deep that got caught up in the upsurge.
09-14-00, 02:17 AM
Speculation arises that before the Biblical Great Flood there was a water vapor canopy over the earth and that canopy caused animals and people to live at close to 2 atmospheres. People lived alot longer then and grew significantly bigger. Extrapolating that to the depths of the ocean should not cause surprise findings. Living in higher pressures brings longer living. Changing pressures rapidly, as indicated previously, brings shorter life spans-Ha Ha.
my dad was telling me once about how in a college bio class, they pute a .22 bullet into a small fish, then pute them back in the water, the fish were about 5 feet deeper than normal, but by the next dayt ehy were back to the normal level, i suspectr this is cause from tehm reajusting there damned swim blatters (i jsut had to cuss)
now about deep marine life, i think there is a highly intellegent speciesliving down there, just like in the movie abyss! j/k though it is possible, we were created on land, and they still have miles and miles to evolve, though nothing mroe to evolve tpoo unless some radioactive caffine drove weired humans from a air transpoted city of atlanta that sank due to a over pop. in which all the populartion evloved, due to caffine spillage, in wich they all grew tail and turnined into fish people, including the cornal! so i guess that goes to show,watch out for the collasal mouth bass!!!
when christianity ruled the world, it was called the dark ages!
THANK GOD FOR ATHEISM!
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Dex- The only way your evolution theory could work was if they a) watched too much Futurama or else b) moved to Redding, California and started going by the screen name of dexter.
Hey, wait a minute...
[This message has been edited by Oxygen (edited September 15, 2000).]
Interesting and funny.
It's all very large.