2006-06-11 06:10:59 · 8 answers · asked by St Lusakan 3 in Science & Mathematics ➔ Biology
Salmon don't find their way to where they were born.
Salmon are born in freshwater streams and move into the ocean as they age. They move back into freshwater to breed, but they DO NOT move back to the same stream where they were born. They will move back to any old stream, and not uncommonly they don't even breed on the same continent, much less the exact same stream where they were born.
Salmon find thier way form the ocean to freshwater simply by following their noses. They can "smell" the mud carried by rivers as well as being able to detect changes in salt concentrations. They simply keep moving until the water becomes fresh and clean enough to spawn in.
It is neither navigation nor divine guidance. Rather it is simply an ability to know how clean the water is that they are swimming in and to move towards cleaner water.
2006-06-11 12:46:30 · answer #1 · answered by Anonymous · 0⤊ 1⤋
I was watching animal planet and it was talking about animals that have some sort of magnetized cells or organism in their head, so they can use the north south directions to get oriented, like birds for example, and even these termites in africa. So it sounds like maybe the fish have it too.
2006-06-11 14:04:48 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Instinct.
2006-06-11 13:12:31 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Aliens implant a special tracking device inside of their brains so that they can tell the fish where to go.
2006-06-11 13:12:59 · answer #4 · answered by ^v^ 4 · 0⤊ 0⤋
A road map
2006-06-11 13:37:24 · answer #5 · answered by ellysium06 3 · 0⤊ 0⤋
Built in genetics and instinct. Wish we were that good at finding our way around!
2006-06-11 13:13:57 · answer #6 · answered by Anonymous · 0⤊ 0⤋
instinct
2006-06-11 13:13:05 · answer #7 · answered by Georgia Girl 7 · 0⤊ 0⤋
they just want to go home
2006-06-11 13:15:19 · answer #8 · answered by myangel_101211 7 · 0⤊ 0⤋