I WOULD LIKE TO KNOW WHERE I COULD GET INFORMATION REGARDING WHY FISH FLOAT ON THEIR WHEN THEY DIE?
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For the same reason a board floats flat instead of verticle. Fish are generally a flat species (except for catfish and a few others). The flat side occupies more surface area and it will just naturally lie flat. Usually they only float when decomposition creates internal gasses inside them anyway. Most dead fish will stay suspended or settle to the bottom until this natural process begins.
A fish species with a ductless swim bladder will tend to float up quickly after death because there isn't a living system to regulate the volume of gas pressures within. It will depend too upon what state the swim bladder was at and at what depth of water the fish was at at the time of death.
The species with a ducted swim bladder can empty gaseous contents into the water directly, and may never make it to the top if stomach and intestinal tract are devoid of food.
With each type, as George has already pointed out, gases produced by bacterial decompositions will "balloon out" the intestines and stomach to produce a bouyant fish whose muscle mass is of a lesser density than water.
I'm assuming you are asking your question in regards to aquarium or pond fish. If that be the case, you will need to recognize clinical symptoms prior to death.
Tropical Fish Hobbyist Publications (United States)has available a book on Fish Pathology. You should be able to order it through a pet shop and can probably find it available on-line. After that you will probably have to go into European Carp farming literature to collect your answers.
Why does dropped bread always land butter side down? Why? Why does a thrown cat always land on it's feet? Why? If you tape a piece of buttered bread to a cats back and throw it, will the cat land on it's feet,.. or will the buttered bread hit first? Who knows? Two of the strongest forces in nature fighting each other,.. it could go either way! but why?
They land of thier head for some reason.
As for bread landing butter side down, try using light margarine.
Butter is heavier and cats have balance. Next? hahahaha, just funnin!
Take a five dollar bill. Flatten it out. Now drop it to the floor. You will notice that as long as it lands flat, Lincoln is always looking up. Why?
I'm impressed by your answers! I really am.
I just want to add that some game fish species that have ducts connecting their air bladders to their stomachs are trout and salmon and catfish which allow them to move quickly up and down in the water column. Other species if caught deep, and brought up quickly to the surface by anglers will experience "the bends" and also virtually inflate on their way up. They will be severely stressed and will have trouble going back down. Many gamefish brought up out of deep water and release will eventually die. Many anglers are unware of this.
The answers as to why fish lie on their sides are appropriate. what burns my ass is folks that still think heavier things fall faster than lighter things. Newton disproved this a while back! Hammers do not fall heavy end first. A marble and a bowling ball dropped from the Leaning Tower hit the ground at the same time. Butter on bread will not make it always fall butter side down. This is the 20th century is it not? Wake up boneheads!
I realize we are a well rounded bunch of nitwits that know a little about everything.
If there is a nuclear halocaust and the world ends up looking like a Mad Max film or Waterworld, most of the survivors will be taxidermists. No doubt about it! And we'll look just as grundy they do in those films.
If you drop a bowling ball and a feather off the empire state building, I guarantee you whoever gets hit with the ball will be dead long before the feather hits, however, They will fall the same in a vacuum. I bet your the one with a puzzled look whenever some cracks a good joke. Just kidding.
A steel ball the size of a marble and a steel ball the size of a basket ball would hit at the same time, but not a marble and steel ball. Wind resistance and air will stack up.
My grandpa caught some perch in abot 60 feet of water once in Canada and the air bladders were spit up on every fish as it surfaced, all already dead from the quick rise to the top.
My suggestion is that the shape and placement of the less-dense parts of the fish cause a fish without fin movement to float either sideways or upside down. The bones and solid meat dorsally is heavier than the belly and lungs and empty spaces not filled with water. Even fish bellies have air in them aside from the air bladder. One thing I have noticed in gutting many fish, is that there is commonly stones in the stomach. Whether these are swallowed as ballast or by accident, they certainly serve no function in any digestion as in stones in galiformes gizzards. They may help in righting the fish. Sick fish, or those dieing, can't maintain fin movement which would keep them upright - either that or they need tums.
I would like to know what type of fish you are talking about. I have never seen a fish with lungs before. I always thought all fish had gills.
Paul B
However, a good argument could be made that the air bladder which occurs in fish is in essence a precursor to the lungs found in amphibia. My faux pas. I meant to say abdomen contents - i.e. liver, intestines, etc. Keep me honest, I hate to make mistakes. Thanks PB.
Besides, haven't you ever heard of Lungfish? see http://www.neosys.ne.jp/neo/english/HG01.html (see fish can have lungs)
Its not the bends, See Boyles Law. this the absorbtion of nitrogen into the body tissues and the exchange of gases on the way to the surface.
In short when a fish of human rises to fast in the water colum the nitrogen will release from soft tissue and cause the blood to have bubbles in it. This can usually be called Decompression illness, may be as simple as tingling skin, or a rash, or a Anyourisam (sp) When the later occurs, death can be the result or stroke.
How you ever noticed as you go deeper in the water your head and ears start hurting?
You make your ears pop, to EQUALIZE PRESSURE, this relieves the ambiant external pressure. 33 feet is equal to how many atmospheres?
After the first six feet in the water colum, you will feel this pressure.
The deeper you dive the greater your chance of Nitrogen Narcosis. Better have your head screwed on straight! It like getting drunk, very drunk.
You are limited to depth you can dive, because of this, even to the point where external pressure on the tank reduces the amount of air in your tank.
Sport diving tables are directly desended from the U.S. Navy dive tables. The deeper you go the less time you can stay, because of Boyles law. Even the builder of the Golden Gate Bridge suffer Caisons (the bends)
With out digging out my set of dive tables, I can tell you the sport diving indursty limits all open water rated divers to 100 - 130 depending on certifing agencies.
How ever with advance tables, a number of us Arkies do dive deeper as deep as 300 feet. This is generally a bounce dive, or decompression stops are required during accent.
What cause the fish bladder to extend into thier mouth, is the expansion of gases, the fish does not get time to decompress.
Here is what is so simple about returning a fish to the water.
Using a hypo needle and barrel without the plunger, insert the assembly into the bladder and degass the fish. Really simple and the fish have enough brains to head for the deep!
If a fish was traveling in space at the speed of light and turned the headlights on...would they do any good?
And why is it, sometimes when you drop your can of pop, it lands upright and doesn't spill? Lucks Law perhaps.
Light must be reflected from some object in order to be of any good. In a large meteor shower or a place in space with lots of dust, headlights could be benefitial, but in a vacuum with no particals, they would do nothing. However, if the fish was traveling at the speed of light there would be no time for light to bounce back, since light travels at the speed of light. I think Eistein did postulate light can bend though, so IF you could get the light to bend, the route would be longer, and therefore... A witch would weight the same as a Duck (or very small rocks)...which is why she turned me into a newt (which has lungs by the way)
My impression is that Juanita is a younger person and we have just messed her head up real bad.
Is it only me that thinks these forums have gone downhill?
Hope we didnot freek the young one out.
Theroy of relitivity.
When you travel the speed of light, time comes to a stand still. Once you pass the speed of light it actually slows down.
Last October three sceintist using Atomic Clocks. flew from the D.C. area to Las Vegas. All three clocks lost 18 seconds. The standard for this test was using the most acurate electronic timer against the Atomic Clocks.
On the return flight the Atomic clocks gained only 17 seconds.
Just something I heard on National Public Radio last week. in a News release from Nasa.