[OT] Salmon and Fish Jumping

Talath · Mar 31, 2003

As I was watching a friend's fish in the tank, he said that fish can jump and I told him it's impossible. I argued with him, because my elementary school science teacher explained it to me and I always believed in it. He explained it as thus:

Around spring, water becomes depolarized and fish become polarized due to subtle shifts in the magnetism of the earths core. Around spring, these factors weaken gravitys hold on fish, allowing them to jump upward at great length. An otherwise impossible feat.

So, can fish just jump, or is my science teacher correct?

alsih2o · Mar 31, 2003

did he also tell you the u.s. is about to convert to metric time?

kengar · Mar 31, 2003

Around spring, water becomes depolarized and fish become polarized due to subtle shifts in the magnetism of the earths core. Around spring, these factors weaken gravitys hold on fish, allowing them to jump upward at great length. An otherwise impossible feat.

uhhh. I'm no physicist or icthyologist (sp?) but that sounds pretty nuts to me.

What about fish that jump at other times of the year like flying fish (I know they have "wing-fin" thingies, but they gotta get out of the water somehow don't they?)

Also, what about aquatic mammals like dolphins that jump all the time, their bodies aren't that different from a fish's in shape.

Aeolius · Mar 31, 2003

Try keeping a wrasse in an open-topped saltwater tank. It doesn't matter what time of year it is; the fish will jump out of the tank. I have lost many fairy wrasses because of this.

On a side note, needlefish have been known to leap from the water and impale nearby swimmers.

Harlock · Mar 31, 2003

Duh, of course a fish can jump. I can prove it by looking at only the first four definitions on www.dictionary.com

1. To spring off the ground or other base by a muscular effort of the legs and feet.

Okay, by this definition a fish cannot jump. Fish live in water, not on the ground for the most part and do not have legs AND feet.

2. To move suddenly and in one motion: jumped out of bed.

This at first sounds like a fish can jump. I mean they always move suddenly and in a smooth motion. Ever seen those schools of fish responding almost as one giant entity to a threat? But we call that swimming, do we not? Yes.

3. To move involuntarily, as in surprise: jumped when the phone rang.

As this really isn't jumping as defined by the original poster, we'll give him the benefit of the doubt.

4. To parachute from an aircraft.

Here is where we see that a fish can indeed jump and it has nothing to do with depolarization and magnetism. You can give a fish, ANY fish a parachute and push it out of an aircraft and it has jumped. I rest my case.

Datt · Mar 31, 2003

Have you never been to a Sea World type place where they had dolphins? They jump all the time in thier shows. They jump over people, they jump up to get a fish being held by a trainer.
Yes fish can jump.

As to the explanation that your friend gave he is talking about how Salmon swim up stream in the spring since the northern waters aren't as hot as the southern waters. And yes they also can jump. They jump to get over rocks and small cliffs in the stream. It is really a cool site to see. I know there is a comercial going around right now, can't remember for what though, that shows fish jumping out of water and a bear grabbing one just as it leaves the water. That is how Bears "fish" during the spring.

Harlock · Mar 31, 2003

Datt said:
Have you never been to a Sea World type place where they had dolphins? They jump all the time in thier shows. They jump over people, they jump up to get a fish being held by a trainer.
Yes fish can jump.

Umm, excuse me for interrupting, but dolphins are not fish. It took only one definition from www.dictionary.com to refute your claim that they are.

1. Any of various marine cetacean mammals, such as the bottle-nosed dolphin, of the family Delphinidae, related to the whales but generally smaller and having a beaklike snout. (emphasis added.)

redknight · Mar 31, 2003

The dolphin (delphinidae) is not a fish. However the dolphin is also a fish related to the more common perch.

1. sea animal related to whales: an intelligent marine mammal (cetacean) that resembles a large fish and has teeth and a snout similar to a beak. Found almost worldwide, dolphins are related to whales but are smaller. Family Delphinidae.

2. large marine game fish: a large sea fish of the perch family, popular as a game fish, that has a long dorsal fin, high blunt forehead, and a brilliant green, blue, and yellow body. Latin name Coryphaena hippurusCoryphaena equisetis. Also called dolphinfish Also called dorado

Harlock · Mar 31, 2003

redknight said:
The dolphin (delphinidae) is not a fish. However the dolphin is also a fish related to the more common perch.

1. sea animal related to whales: an intelligent marine mammal (cetacean) that resembles a large fish and has teeth and a snout similar to a beak. Found almost worldwide, dolphins are related to whales but are smaller. Family Delphinidae.

2. large marine game fish: a large sea fish of the perch family, popular as a game fish, that has a long dorsal fin, high blunt forehead, and a brilliant green, blue, and yellow body. Latin name Coryphaena hippurusCoryphaena equisetis. Also called dolphinfish Also called dorado

Yes yes, but the fellow was obviously referring to the Sea World trained dolphins which are in fact mammals and therefore not at all a fish and hence not relative to this discussion of fish-jumping.