Which is the most primitive freshwater fish species?

[Ichthyotopia]

interesting, must of still been a cool fish to have for a lil.

what do u make of this diagram.. it seems to claim that polypterus is more primitive than chondrichyes

http://www.cob.lu.se/phylogeny/

 

[lpkoh5]

bichirs for sure.....

 

[Ichthyotopia]

http://www.cob.lu.se/phylogeny/vert_tree.html
http://www.cob.lu.se/phylogeny/proj_descr.html

this study goes against what we had been saying was true. do u suppose this is really how it is?

 

[spwd]

Very interesting guys keep it up.

 

[HungDang]

as far as I know, ray/shark families(fresh water rays, bull shark) are probably the fish fish to come to fresh water then go the bony fish(sturgeon,gar, arowana, knife,...)!

 

[Wiggles92]

http://www.cob.lu.se/phylogeny/vert_tree.html
http://www.cob.lu.se/phylogeny/proj_descr.html

this study goes against what we had been saying was true. do u suppose this is really how it is?

Scientists keep flip-flopping on this stuff, so who knows at this point.

 

[Ambervikings91]

cool thread

 

[DariusAmurdarja]

Bichirs are by far the most primitive fish you will find. They date back till the early devonian. There is a large fossil gap but that doesn´t mean they weren´t there back then. Their general body is similar to Hyneria and other devonian fish. They are used as rolemodels for those devonian fish cause they come closest to them.

 

[SimonL]

Bichirs are by far the most primitive fish you will find. They date back till the early devonian. There is a large fossil gap but that doesn´t mean they weren´t there back then. Their general body is similar to Hyneria and other devonian fish. They are used as rolemodels for those devonian fish cause they come closest to them.

By far? You could keep (and some members do) lampreys if you wanted. Stingrays and sharks also predate bichirs if I'm not mistaken.

 

[DariusAmurdarja]

By far? You could keep (and some members do) lampreys if you wanted. Stingrays and sharks also predate bichirs if I'm not mistaken.

It is debateable if sharks predate bichirs, since the first real known shark cladoselache appeared in the mid devonian, while the first acanthodii can be dated back to the silurian. That means, that the anchestors of bichirs predate the first sharks around some 50 million years. Lampreys could be older but we have no fossil evidence yet. The oldest known lampray is priscomyzon and dates back to the devonian. Rays on the other side are a very "new" form of fish. The oldest known rays come from the jurassic.

The oldest and most primitive form is the lancelet. But i have no clue if you can keep those things in an aquarium.