Common Name: Strawberry Betta, White Seam Betta
Description: A small but fierce maroon and black labyrinth fish with white-margined fins that lives in East Kalimantan blackwater swamps. Their colors intensify or fade to golden-brown depending on their mood and their environment, like tiny chameleons with a limited color palette. Betta albimarginata is closely related to Betta channoides, which is stockier than B. albimarginata and doesn’t have a white margin on its dorsal fin. CARES lists Betta albimarginata as Vulnerable, but the IUCN Red List lists it as Endangered.
Category: Anabantids
Global Region: Southeast Asia
Distribution: East Kalimantan, Indonesia
CARES Classification: Vulnerable
Collection Point: Malinau
Genetic Line: Other
Year Acquired: 2024
I bought my first pair from Moonlight Aquatics in June 2024. The store's owner said they were captive-bred and genetically from the Malinau locality, but he wasn't sure how many generations they were removed from wild caught parents. I tried reaching out to the person he got them from but received no response. In 2025 I traded some of my original pair's offspring for a female bred by a GSAS Aquarium Club member, the female's lineage tracing back two generations to parents also from Moonlight Aquatics (almost certainly parents from a different export by the same breeder). Later in 2025 I also purchased four F1 unsexed juveniles from inmytanks.com. The seller says they're also from Malinau. Due to some minor differences between the two lines of fish however, they're possibly from different areas of Malinau.
While both have two black or very dark brown longitudal lines running the length of their bodies made up of overlapping markings (looking like short vertical pen marks or paint splashes), the first bloodline's longitudual lines are more or less continuous, while the second bloodline's longitudal lines have more visible gaps, making them look spotted. The second line's red coloring is also slightly brighter, and there's more of a contrast between their fin's white margins and the rest of their fin when they're younger.
Spawning notes:
Species Spawned: Yes
Spawning seems to be triggered best by feeding the parents very well for a week or two, lowering the water level, not feeding the parents or feeding the parents lightly for a day or two, and then adding reverse osmosis water and feeding the fish plenty of food, but I'd need to experiment more to know for certain.
I've had them successfully spawn in softer water and neutral PH water, but most of my spawns have been in neutral water, quite possibly because that's just how I keep most of my tanks. I've had spawning in tanks with a single pair of bettas and in tanks with several fish, but spawning seems to happen more frequently in a single pair environment. I've had them spawn in tanks with and without botanicals, and with varying levels of lighting. Both males and females have initiated spawning. Heavily planted tanks or tanks with other barriers breaking lines of sight have proven to be helpful, as it gives the fish a break from one another if they need, and gives males places to hide when they're holding eggs. (This takes about 14 days.)
I would not recommend keeping two females and one male in a tank. The only time I've had actual violence in my tanks is when two females started fighting over the single available male (who did not seem to care and spawned with both). I realized and separated them out before either female had any lasting damage, thankfully.
It's also important to give males a break between spawns. They don't eat while they're holding, and some particularly enthusiastic ones will spawn a day or two after releasing their previous spawn, putting them at risk of starvation.
Have Reared Fry? Yes
Betta Albimarginata fry are generally very hardy and easy to care for. They won't recognize food as food unless it's wiggling, but they can eat baby brine shrimp from day one. They do best being kept to a small area for the first month or two of life, since it makes it easier for them to hunt down their food.
The most difficult part of rearing them has been keeping their parents from eating them. Some people report having no problems, but for some reason, all of the males I've had hold so far (all directly related, most of them with multiple spawns) will release their fry, then once the last fry leave, immediately chase them down and start eating them. The newborn fry, which rest almost motionless at the surface for their first few days, are well-camouflaged but easy pickings when they drift from their chosen leaf or plant.
The window between when the last fry is released and when their fathers suddenly see them as food is, unfortunately, narrow, seemingly only between half an hour to a couple of hours.
So far my best fry survival percentages have come from moving the male to a heavily planted breeder box when he's close to releasing them, watching him carefully throughout the day, and when he seems to not have any fry left, offering him a small amount of food. If he goes for it, I move him out of the breeder box and feed him. If he doesn't, I wait for more fry and try again in an hour or so. It's not ideal, as I can't always be home to watch him. I may try stripping the next male of eggs and hatching them in an egg tumbler. I've also obtained a couple new males completely unrelated to the ones I already have, and will see if there's any differences in how they hold their eggs. So far I've seen between 2 and 17 fry per successful spawn.
Young fish available? Yes