Yahoo Answers is shutting down on 4 May 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
How did freshwater fish species spread from one drainage basin (river system) to another?
I can't imagine a flood or a course change crossing a watershed consisting of a ridge of high ground (which many are). Transport by people has probably only happened in fairly recent years.
I'm asking specifically about trans-watershed transport, rather than things like isolated ponds getting flooded by a nearby river.
Egg transport by birds sounds probable: is there evidence it happens?
3 Answers
- ?Lv 75 years agoFavourite answer
o as eggs on bird feet?
o otherwise carried by birds?
o squirmed across land (there are a couple of species of fish that actually do this)?
o swam from one to the other during a time of flood?
o carried by people (including "stocked")
o the land has shifted in recent millenia. At one or more times those rivers shared a common source (possibly ice-age repeated inundation).
- οικοςLv 75 years ago
Stream capture, flooding, and trips through saline water from river mouth to river mouth
- Cal KingLv 75 years ago
Mostly through floods. Some fish can also move over dry land. Rivers will also change courses and they may join and disjoin.
