I don't think there has been enough research to positively say what species
will breed with another. Although there has been a fair amount of
crossbreeding reported in the aquarium hobby so I think it would be
reasonable to expect that most species would crossbreed if a suitable mate
of the same species was not available.
Adrian.
...............................................................
Adrian R. Tappin
"Home of the Rainbowfish"
http://www.ecn.net.au/~atappin/home.htm
...............................................................