Spawning Betta smaragdina – the “Emerald Betta
By Yohan Fernando

Betta smaragdina comes from an area that borders Thailand and Laos. This fish was first identified by Ladiges in 1972 and quickly established its place in the tropical fish hobby, especially among anabantoid enthusiasts. The shiny green sheen on the body and fins has led to this fish being referred to by some as the “emerald Betta.”

Betta smaragdina reach and adult size of about 1 ¾ – 2 inches in length. Females of this species are slightly smaller than the males. This fish is easily sexable, even at half its adult size; males have longer ventrals, larger fins and more intense color on the body and fins.

Betta smaragdina are easy fish to spawn. Contrary to what some say, I found the B. smaragdina not to be very fussy when it comes to water conditions. I have spawned B. smaragdina in de-ionized, peat filtered, soft, acidic water with a pH of 6.0 as well as in hard, alkaline, straight Milwaukee tap water with a pH of 7.8. There was no difference in spawn size of growth rate, which makes me conclude that this species, like its closely related cousin, the B. splendens is very adaptable to its environment. However, I did notice a difference in sex ratio. The fish that spawned in hard, alkaline water yielded a higher percentage of males.

I have successfully spawned this fish and raised a good number of fry using a very basic breeding set-up. I use either a divided 10 gallon tank, a 5 ½ gallon tank or a 10 gallon tank for breeding. I prefer to use seasoned, fully cycled tanks as these tanks hold an abundance of infusoria, which will provide a life source to the fry in their initial life stages. I lower the water level in the tank to about 4-5 inches. I use a small seasoned sponge filter and adjust the airflow so that it releases 1 bubble per second. A clump or two of java moss and a couple of clay pots are added to provide cover for the female. I introduce either a split Styrofoam cup or a floating nesting site made from 2 pieces of 1 ½ – 2 inch diameter, 2 inch long PVC tubes siliconed to a floating rectangular piece of polystyrene. A tight fitting hood is a necessity to breed and raise a successful spawn. Like all Bettas, B. smaragdina are great leapers and a tight fitting hood will not only keep the breeding pair inside the tank, it will also prevent cold air from hitting the tank surface. Cold air skimming the water surface of the breeding tank will destroy a young spawn in no time. It is critical that the temperature of the atmospheric air and the tank water are the same, especially during the stage where the labyrinth organ develops in anabantoids.

It is important to condition the breeding pair separately for at least a week before any spawning attempt. I use a combination of adult brine shrimp, white worms, black worms and freeze dried bloodworms to condition the fish. I do not recommend administering this high protein/fat diet as a staple diet, since it could cause liver damage resulting in dropsy.

After the pair has been well conditioned, I introduce the male to the breeding tank. About 2-4 hours later, the female is introduced into the tank. Within a day or so, the male will build a bubblenest under the split Styrofoam cup or inside the floating PVC tubes. Spawning will follow in the same manner as in B. splendens, however, with less aggression. The male does chase the female around the tank prior to spawning but there is very little fin tearing or damage to the female. The spawning lasts for about 2-3 hours. Like B. splendens and B. imbellis, the female is chased away as soon as spawning is completed. At this point, I take the female out. The eggs hatch within 24-36 hours at a water temperature of 82 degrees Fahrenheit. Once the fry are free swimming, I take the male out.

Feeding practices are the same as for B. splendens fry and other small bubblenesting Bettas. Green water for the first 3 days is my choice of initial micro-food. From this point onwards I feed the fry a combination of microworms and newly hatched brine shrimp. Although it is common knowledge, I will mention that it is important to monitor the water quality at this stage. Overfeeding will increase the ammonia in the tank and this will quickly kill the fry. Partial water changes are recommended every 2-3 days, with water introduced into the tank being of the same temperature as the water in the tank.

The fry will grow rapidly on a varied and high protein diet. Within 4-5 months, the fry will have reached adulthood and will be ready to spawn. This is a fish that will live harmoniously in numbers. It is unnecessary to separate the males, as they generally do not tend to be very aggressive to each other. I’ve had no problems maintaining groups of males and females in the same tanks.

I highly recommend this fish to anyone who is tired of cleaning Betta jars. Along with B. imbellis, B. smaragdina are a good introduction to the wild Bettas.