When we take these four (sub)species theoretically the following crosses could be made:

· Betta splendens x Betta imbellis

· Betta splendens x Betta smaragdina

· Betta splendens x Betta sp. mahachai

· Betta imbellis x Betta smaragdina

· Betta imbellis x Betta sp. mahachai

· Betta smaragdina x Betta sp. mahachai With exception of Betta splendens x Betta imbellis crosses, not much is documented about whether all these species really can interbreed without problems. When we look at the origin of the "dragon" as described above, accoring to Pichet it was not easy to cross the red copper betta x Betta sp. mahachai. Please note that copper is a metallic phenotype which was created by crossing Betta splendens to Betta imbellis, however how many generations this particular fish is seperated from this initial hybridization is unknown. Strikingly, Victoria Parnell-Stark also reported difficulties with the Betta splendens x Betta sp. mahachai hybrids. In both cases it seems that a mixture of these three species was necessary in order to create and fixate a healthy, viable line. So why where some of these crosses difficult? Was this is just a coincidence or could it be that certain species were evolutionary more separated from each other? Does the similarity in appearance between Betta imbellis and Betta sp. mahachai and the readiness to interbreed mean that they are evolutionary closer related to each other than to Betta smaragdina and/or Betta sp. mahachai? Based on their phenotype Betta smaragdina and Betta sp. mahachai also show quite some similarities, does this implicate that they are more easily easily intercrossed than to Betta splendens and/or Betta imbellis? Some other unanswered questions/remarks to keep in mind with respect to this subject are:

(1) Does it matter which sex we use to interbreed species? Are the results different when we breed a male of species A with a female of species B or the other way around?

(2) Are F1 hybrids of the above mentioned crosses normally fertile, and is this sex dependent? It is known that F1 hybrids of two species which are further apart in the phylogenetic tree could be infertile. Does this account for both sexes or is it in some cases possible to use hybrid males or females to cross back to one of the species used in the initial cross?

(3) Can hybridism function as a genetical "bridge" between two distinct species? The idea of the later hypothesis would be that the F1 hybrid offspring of two different species might function as a genetical "bridge" for the interbreeding of two species which are evolutionary further apart.