Ive been going down a Quora rabbithole the last couple of months. In amongst all the conspiracy theories put out (i do enjoy a good conspiracy theory), there have been a few aquarium related topics. These are often AI generated questions and answers to keep the site active, but one answer posted about keeping a betta and guppies together stuck out to me, and the answer was something id never heard before. While the responses where generally negative on doing this, one said that these 2 fish can hybridise, albiet rarely. Any thoughts on this?
I would have thought an egglayer and livebearer would be impossible to hybridise.
Going further is it possible for 2 egglaying fish species hybridising? Say a tetra and a danio? Or 2 different tetras? Or 2 different livebearers? Going back to my angling days hybridised fish where commonly caught. Roach/ bream hybrids where more common than pure bream at my local reservoir. Never really heard of it in an aquarium though.
As Colin stated, hybridizing an egglayer with a livebearer could only be done in a petri dish, not in nature.
You have to remember that hybridizing fish for the hobby has been going on for decades. Just look at the first red swordtail. It was the combination of a red Platy with a green swordtail. Then there's the Muppy ( a Guppy/ Molly hybrid). Most of the offspring are mules ( sterile) but even at one point, only 1 in approx 300 Gold Severums were fertile but with time and selective breeding, that's changed to mostly all of them being fertile. Then you have the parrotfish which is a triploid hybrid. Today's domestic Angelfish have long been suspected of having hybrid ancestry because the different Angelfish species are all in the same Genus. Look now at all the synodontis catfish hybrids and African cichlid hybrids. The tiger shovelnose/ redtail catfish hybrid. Just to name a few.
So the hobby is responsible for hybridizing a lot of fish. ( Not all for the betterment of the fish IMO
)
As for your Roach Bream, maybe it's not the genus that needs to be the same but the family? Both of these fish are in the family Cyprinidae so that may have all that needed to be.
In fishing, there have been many hybrids of Bass created to live in different areas. There's the Northern and Florida Bass hybrid, the White and Striped Bass hybrid, Largemouth and Sunfish hybrids. There's even a Largemouth( spotted)/ smallmouth Bass hybrid ( it's called a "meanmouth".
https://shopkarls.com/blog/meanmouth-bass )
There are multiple natural marine hybrids but the majority of them are in fish that scatter spawn vs substrate spawn. We used to love getting natural hybrids. They went for more money.
One of the rarer substrate spawning hybrids came up in discussion with Julian Sprung ( a former customer of mine when he was a kid
) where he noted that every anemone with a White cap Anemonefish ( Amphirpion leucokranos ) had a skunk clownfish and a Sebae clownfish as well. He surmised that the Amphirpion leucokranos was actually a wild hybrid. It wasn't until decades later that DNA testing, I believe, confirmed this. To my understanding, there is now a second natural hybrid clownfish found in the Philippines. Now, with the advancement of breeding marine fish, they are making hybrid angelfish as well who knows what the next man made hybrid will be.
So you can see, hybridizing has long gone on. The question is, imo, are we being responsible in our man made hybrids?
I'll pose this to tickle your conspiracy funnybone: The fish stocks in the Philippines have long been overfished. I know this because our divers used to tell us how they had to travel far distances to collect fish after all the dynamiting and cyanide use that went on in the near shore areas. So if the fish stock was low, did this second natural hybrid clownfish happen out of a lack of fish to choose from?
