Male Asian Rummynose
The Asian Rummynose, Sawba resplendens, is also known as the “Naked Microrasbora”, “Asian False Rummynose”, “Rummynose Rasbora”, and “Sawbwa Barb”. There still is debate on what group of fishes they belong to: rasboras, barbs, danios, or possibly their own classification. The term “Naked Microrasbora” refers to the fact that they have no scales and are therefore more sensitive to medications, especially containing copper. “Resplendens” refers to the brightness of this fish. They were found in Lake Inle, Myanmar (Burma) South Asia and were described by Annandale in 1918.
Lake Inle is shallow and swampy, with hard, alkaline, peaty water and dense vegetation. The average depth in the dry season is 7 feet and in the rainy season, 12 feet. Water hardness comes from the surrounding terrain which is limestone base rock. It is the second largest lake in Myanmar with a surface area of 45 square miles, and is found in mountainous terrain at an altitude of 2,900 feet above sea level. During February water temperatures can dip down to 57 to 64 degrees, which may be helpful in us understanding how to breed these fish. There are 9 species of fish found nowhere else in the world, including Sawbwa resplendens, the Crossbanded Dwarf Danio (Danio erythromicron), and the Inle Danio (Inlecypris auropurea). 70,000 people live in 4 cities and many small villages bordering the lake. Most are self-sufficient farmers working manmade floating gardens producing fruits and vegetables. Many locals live in stilted homes and use hand powered small boats for transportation. The floating gardens are resistant to flooding since the water level can vary up to 5 feet seasonally. The conservation status of this lake is considered vulnerable due to pesticides, fertilizer, cattle grazing, and sewage disposal.
Asian Rummynose males are very striking with a bright red head and tips of the forked caudal fin, and body of steel blue-grey. Females are silver with clear fins and no red coloration and are usually smaller than the males. They are not often seen in fish shops and there seems to be a preponderance of males in the fish available. This is a somewhat difficult fish to keep due to its sensitivity to water conditions and temperature requirements. It likes to be kept fairly cool in clean, hard water. They show the best color when water temperature is in the low 70s’ and heavy vegetation is present, including floating plants. They are found in the wild in very large schools and become quite shy in an aquarium unless there are 6 or more together. Being from a lake, it probably does better in quiet waters without heavy aeration or power filters, so sponge or box filters might work better. To harden the water, a box filter filled with dolomite or coral gravel works nicely. They are very peaceful and only should be put with other small peaceful fish. Best would be a species tank. This fish is lively but somewhat nervous so it frightens easily and is a jumper, so keep their tank covered! It is a small fish, rarely getting more than 1 ½ inches.
The Asian Rummynose eats most all foods but needs some help to take flake foods. It should be fed a variety of foods, including spirulina for vegetable matter, but live and frozen foods should be fed as their staple. It has a small mouth, so larger foods should be avoided. Live baby brine shrimp, small daphnia, black worms, and grindle worms are some of their favorites.
My success breeding Sawbwa resplendens has been very limited, having collected some eggs and raised a few fry. Many have had difficulty breeding this fish, and my hope is that information I have gathered will stimulate others to be more successful. I set up a young healthy pair in a 2 ½ gallon tank with a small crushed coral undergravel fiter to harden the water. Sexing is easy, as the female is smaller with no color in the nose or tail. Live or plastic plants and a mat were used for cover. After about a week, the pair was comfortable and eating live and frozen foods well. Water temperature was 75 degrees and regular water changes were being done. The female seemed full of eggs and the male colored up well, but no eggs were collected for a long time (the gravel or mat is siphoned with a cylinder siphon and that is checked for eggs). Finally, in desperation, I made a 2/3 water change with RO water and began finding some eggs. I suspect the drop in water hardness imitated what happens at the start of the rainy season in lake Inle, which is likely when they spawn. The eggs were small, clear, and few in number. They were hatched in a 1 gallon jar of medium-hard water with methylene blue to reduce fungus. In 2 days the eggs hatched and the fry were thin, glasslike slivers with a large head. They began to swim slowly in a tail-down fashion with a bend at the neck, and are adept at hiding. It was necessary to feed infusoria or APR for over a week before the fry would take baby brine shrimp. The fry seemed difficult to feed and sensitive to pollution, and I managed to only raise 3 to maturity the first time. Subsequent spawns have produced more fry, but never in great numbers. They are slow growers and mature in 6-9 months. The eggs of this fish may be adhesive, and some reports indicate they lay them on the underside of broadleaf plants. Because they are shy fish, subdued lighting may help in getting them to breed.
The Asian Rummynose is one of the most attractive small cyprinids in the hobby. They maintain popularity despite limited availability. I encourage others to try them, since the more we learn about keeping and breeding them, the more available they will become.