Which is the most primitive freshwater fish species?

[Oddball]

Yes, you can keep lancelets (Amphioxus) in aquaria. There's a biological supply house that sells them for classroom and lab studies.

http://www.monsterfishkeepers.com/forums/showthread.php?21936-Older-Than-Dinosaurs-The-Lancelet

 

[DariusAmurdarja]

Yes, you can keep lancelets (Amphioxus) in aquaria. There's a biological supply house that sells them for classroom and lab studies.

Could you give me a link please? Would be cool to have.

 

[framcosco]

Yes, you can keep lancelets (Amphioxus) in aquaria. There's a biological supply house that sells them for classroom and lab studies.

http://www.monsterfishkeepers.com/forums/showthread.php?21936-Older-Than-Dinosaurs-The-Lancelet

Thank you for the link Oddball. Wonderful read.

 

[Ichthyotopia]

thanks for bringing this thread back to life guys, great info
I didnt even know there were living "fish" that are older than lampreys.

Yeah ditto, that link would be cool if u dont mind posting it oddball.

 

[SimonL]

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.

Bichirs aren't Acanthodians though, I'm not aware that they even had a speculative phylogenetic relationship. I'd love to see a source for that, did you have one regarding polypterid evolution?