Viewing a single comment thread. View all comments

craigery_t t1_ism29va wrote

Reply to comment by GreenStrong in How do fishes get into isolated inland lakes in the first place? and why don't we see more divergent evolution / speciation given the separation of each group of fishes from each other? by I-mean-Literally

This is new? I've been told this as long as I can remember.

7

PhotoJim99 t1_ismc8cu wrote

Perhaps you were told it as speculation, and now it's been scientifically verified.

45

antij0sh t1_isnr3dj wrote

It’s still not “scientifically verified” that bird feces is the vehicle for this phenomenon, it’s only been shown in this study that it’s possible for some eggs to survive digestion.

14

PhotoJim99 t1_isqnsy4 wrote

Fair enough, but that's still a significant step forward from "speculated".

2

cacomyxl t1_ist1hnx wrote

I think people have mentioned it, but this seems pretty conclusive to me.

Experimental Evidence...

And just like the raft theory of island population by land animals, it only take one incident over a period of many thousands or millions of years.

2

katiekat122 t1_isp9s0j wrote

Alot lot are stocked by humans. I can only speculate but humans also fish with love bait etc. shiners. Im sure there are others that are used this may add thought to your question.

1

amaurea t1_isxc6ui wrote

Are you sure you're not confusing it with the old "brought along with feet and feathers"-hypothesis? The abstract of this recent paper (2020) says the gut hypothesis was only suggested recently:

>Fish have somehow colonized isolated water bodies all over the world without human assistance. It has long been speculated that these colonization events are assisted by waterbirds, transporting fish eggs attached to their feet and feathers, yet empirical support for this is lacking. Recently, it was suggested that endozoochory (i.e., internal transport within the gut) might play a more important role, but only highly resistant diapause eggs of killifish have been found to survive passage through waterbird guts. Here, we performed a controlled feeding experiment, where developing eggs of two cosmopolitan, invasive cyprinids (common carp, Prussian carp) were fed to captive mallards. Live embryos of both species were retrieved from fresh feces and survived beyond hatching. Our study identifies an overlooked dispersal mechanism in fish, providing evidence for bird-mediated dispersal ability of soft-membraned eggs undergoing active development. Only 0.2% of ingested eggs survived gut passage, yet, given the abundance, diet, and movements of ducks in nature, our results have major implications for biodiversity conservation and invasion dynamics in freshwater ecosystems.

1