Not impossible. According to some research a friend of mine is conducting on some of the out of the ordinary hybrids available to catfish hobbyist. Apparently there may be something in a catfish' genetic makeup that makes it more susceptible to hybridization. Hence why we've seen stranger things like TSN x Niger catfish. Don't rule out any hybrids when it comes to catfish. There's stranger crosses out there than what we've seen in the USA.