Not true you x=cabbot keep more than one pleco in a tank.
I have been spawning plecos now since about 2003. Today I have about 400-500 plecos and they are in roughly 18 tanks, But I recently shipped out about 80 of them. I had 100 L2173 in a 125 gal. I heep breeding groups of 10-15 fish in a 33L and then they spawn and I get more plecos.
I breed all Hypancistrus from the Rio Xingu now but I have worked with other species in the past. I always do species tanks. They are loaded with caves and a ton of rock and wood.
However, when one tried to mix different pleco species, this may or may not be a problem depending on the species and the tank involved as well as the scaping inside that tank.
I just sold my 11 breeder group which were spawned from TR parents. Along whith them went 113 assorted offspring from that tank. i got the 11 breeders in Earl December of 2015. They came in as 14, but when I got my wild caught groupt of 10, I sold 4 of the 14. I soled those same 11 fish last month. there were also another 75 or so offspring from them in the tank.
The fewest number of plecos I have in any tank today is 4 zebras in a 20L, another 7 huge adult zebras in another 20L and 2 x 6 173 and 1 x 7 in smaller spaces. All are for sale. However, I have many more tanks with 20-40 plecos in them.
I have been doing this nw for close to 20 years. I started with TR strains of bristlenose. They had no problem being on larger populations in the same tank.
Now for the kicker. Ihave this many pelcos because they pay for my hobby costs and the insane prices I have to pay to acquire them. They sell for at least $50 for the cheapest/smalles and as proven breeder tehy will run #300 to about $700. If these were regularly killing each other I would have to be crazy to house them in numbers.
That said, I am sure mixing certain species under specific circumstance can and does sometimes lead to a fight to the death. It would depend upon how each fish perceived the other. But one cannot say that it isn't safe to house any 2 plecos together because it simply is not the case.
p.s. Before I began breeding Hypans I kept a "Yipes Stripes" pleco tank: zebra, L66, L134 (now P. compta) and L333. I did lose 3 of the 5 zebras that went in over time. I never lost any of the others. I think the zebras being the smallest of the species may not have been able to compete for food. I also did not have an adequate number or size of caves either.
