Care and Spawning of Betta smaragdina
by Gerald Griffin (Mar/Apr 1990)

Betta smaragdina has been in the aquarium world for quite a while but generally has not been too available to aquarists. This is really quite a shame as it is one of the most beautiful little gems to appear in the aquarium hobby. Betta smaragdina has the synonyms ’emerald fighting fish’ and ‘peaceful Betta‘. The fish can be a very combative species. This fish is overall a dark red that is overlaid by a brilliant green iridescence, which is quite intense. Females are also this color but the iridescence is less brilliant than the males. Kept under good conditions this Betta actually keeps his color quite well in the aquarium.

The water conditions are not that critical, but should be kept clean and well aerated. Hardness should not be extreme, but my water quality is at 170-200 ppm and pH of 7.4 – 7.6 and many of my Bettas do not show any discomfort and I have bred many wild species. The tank conditions are however critical. This fish needs some hiding places where it can feel secure. Also it is best to keep equal numbers of males and females, or more females than males, so that fewer fights will break out. With these conditions met, Betta smaragdina is quite a lovely addition to any tank.

Breeding Betta smaragdina is also easy. They breed in much the same way as Betta splendens except for the female is placed in the tank at the same time as the male. It has been my experience that the water temperature should be 78 to 80ºF. The males are just as unpredictable as Betta splendens, but generally will not harm the female. The male will build a nest and its size is highly variable. I have seen nests the size of dimes, nest half the size of a 10 gallon tank and I have seen them spawn with no nest at all, (all from the same male), so there is no rule to nest size. The female is removed after the eggs are spotted and after spawning is complete. The male may be fed during tending. I feed all my wild nesters while tending and have never seen them devour their young, and have raised many large spawns. The fry will be free swimming between four to five days, at which time they may be fed baby brine shrimp. The young grow about as quick as splendens. From here there are two ways to treat them. Method one is to place the ones you want in other tanks and let them grow. Method two is to jar them like splendens and raise them to maturity. Two important notes: One, keep your jars covered. When I buy mason jars I keep the lids and punch feeding holes in them; and two, Bettas removed from the tank and placed in jars will fight just like splendens. Jarring a portion of your males will allow you to keep more females than males in a show tank.

Betta smaragdina has also been the subject of selective breeding as well as Betta imbellis and Betta splendens. The smaragdina also has a wild “red morph” form in which the red is a brighter color and has limited body iridescence. The mutation are longer fins (not quite the size of splendens), a white smaragdina (so called because of the lack of color), what has actually happened is that this fish appears to have constricted chromataphores and during intense fighting or breeding enough of the hormone that caused color is released and the fish then turns a washed out color, and a blue. The blue is actually what it says, this fish has some blue iridescence to it, not much, but with time these mutations will be worked so that they may one day rival splendens.