Originally Posted by 1fish2fish
This would be an interesting article if it weren't full of myths LOL
First off.. no tail type is more or less aggressive over another. With PK some fish are more closely related to "fighter" types so they will be more aggressive but if you get a PK from a well established line you may find that they are not aggressive at all. Conversely you can get HMs that are extremely aggressive, so on and so fourth.
Second. Betta raja is a mouthbrooding species so there is NO WAY that they would hybridize. Betta raja may be a little bigger than splendens (I've never seen one personally) but they are suggested to be housed in 10 gallon tanks (pairs) so I doubt they're very big.
Raja is big compared to splendens but I never knew it was a mouthbrooder, which explains the size. CTs and PKs CAN be more agressive but I've had HMs be equally aggressive or even worse. Like you said 1fish2fish PKs from a good line aren't as agressive (my dragon genos from the_K didn't harm each other at all).
But I agree, people should actually attempt some basic research before saying that a certain strain is this or that...especially if what they think includes an impossible hybrid.