Betta splendens, the domesticated Siamese Fighting Fish

Betta splendens (Siamese Fighting Fish). Splendens does mean "splendid," just as you always figured it did. But did you know that when they were exported to Europe they were first bred in France, in 1893? The splendiferous veiltail bettas have been selected over generations, and may have hybrid origins in crosses with closely related wild forms of Betta imbellis and Betta smaragdina, The wild bettas are still found all through the lower Mekong basin in Thailand and Cambodia, but in areas near cities escapes and discards of the aquarium strains have bred back with the genuine species; this is probably the origin of the Betta "Mahachai", found near a town 20 miles from Bangkok, where the local wild strain has a high reputation among Thai breeders of Bettas for fighting, the pla kat. 
 
The stockier, duller-colored strains cultivated in Thailand for fighting and known as plakat bear little resemblance to long-finned aquarium strains of the last hundred years. Betta splendens does not occur in nature. When the ichthyologist Charles Tate Regan described the "species" Betta splendens in 1910, he was taking the long-finned captive selection as the species' type; he created a knot of problems.  Frank Schäfer, writing on Betta cf. imbellis for Aquarium Glaser, compares the situation to describing the wolf based on a Yorkshire terrier and then attempting to reconstruct the wild original on the basis of the description.
 
A key to the  intricacies of Betta species was unravelled by K.-E. Witte and J. Schmidt, appended to their report of a new species, B. brownorum, in 1992.
 
Still, anyone simply referring to a "Betta" (ever since the Beta-Max fiasco often mispronounced "BAY-tuh" but you'd betta say "betta") usually means one of those spectacular man-made creations displayed in cramped jam jars at your LFS. Some "wild-type" bettas do creep into the market, though; so, if you agree that a fish with two tails is not a lot more attractive than a calf with two heads, you should be glad to know that there are magnificent wild betta species out there, real enough and rare enough to lure even the most fastidious connoisseur. Check out some of the recent discoveries in this genus, made in Sarawak and Sabah and other remote sections of Malaysia during the last decade or so among Betta species at the International Betta Congress website.
 
Details of breeding bettas are familiar: you'll find plenty of stuff in the links that follow. But putting the female with the male can be a little tricky sometimes, even when she looks ripe. Al Castro offered a good trick in Aquarium Fish: he put the female in a glass jar filled to a half-inch from the top, set into the male's tank so that the tank water also came to within a half-inch of the jar's top. When she was ready, she'd jump the jar! (The jar would protect her afterwards.)
 
The male is a famously devoted father, and most aquarists keep him with the bubble nest until the fry are roaming. Even when they're swimming free of their yolk sacs, the male keeps watch for danger, and according to  Stéphan Reebs (Fish Behavior in the Aquarium and in the Wild (Cornell 1991:54) he signals the young, who stay near the surface, by shaking his pectoral fins near the surface; they feel the vibrations and head towards their source, where he takes them in his mouth and spits them to the safety of the nest. This is a detail I don't remember reading elsewhere.
 
Links. There's so much posted on the web about Bettas. A good place to start, with basic information about keeping Bettas and the various techniques for breeding them, is at Victoria Stark's BettySplendens site.