Tan & Kottelat 1998
Tan & Kottelat 1998
Betta falx male
Photo by Kei Sasaki (Betta House) 
Keeping Betta falx from an Aquarist View
Betta falx can be housed in pairs, species tanks, and community tanks. Pairs can be housed in a 2.5 gallon tank, groups should be housed in a 10 gallon tank or larger. Pairs should be given cover such as caves and plants. In a pair or species situation it is possible that fry could be discovered in the tanks. For best results remove a brooding male.
Not critical, falx is very tolerant of water chemistry and thrives in almost any type of water as long as it is clean and well filtered. They should be kept at cool to mid 70s F.
Males have a broader head then females and a much darker stripe on the anal fin. Females may not have a stripe or faint stripe on the anal fin. Females ovaries might be visible via spotlighting.
Falx is a paternal mouthbrooder and the male incubates from 9 to 12 days with 10 days being very consistent. Incubation time can vary with water temperature. Females normally initiate spawning.
|Similar Species||Similar species would be picta complex members simplex, picta and taeniata.|
|Identification||Falx males normally do have a highly pronounced stripe in the caudal fin like simplex where as picta does not.|
Articles on Betta falx
Care and Breeding of Betta falx Gerald Griffin 2003, Republish from Flare Magazine
Articles on related species
Betta picta: Not Very Beautiful, But Interesting Nonetheless– Gerald Griffin, 1988 Republish from Flare Magazine
Betta picta (Sumatra) Yohan Fernando
Betta picta – Carolyn Hanlon, 2007
|Original Citation||Tan, H. H. and Kottelat, M. 1998. |
|References||Tan, H. H. and M. Kottelat, 1998.  Froese, R. and D. Pauly, 2002. |
|Collection Data||22 Jun 1995 Sungai Alai, km 19.5 on Muara Bungo-Muara Tebo Rd., ca. 1°28’42.6″S, 102°18’31.7″E, Jambi Prov., Central Sumatra|
|Paratype||CMK 11119 (44)
MHNG 2593.95 (5)
MZB 9307 (4)
RMNH 33087 (5)
ZMA 121673 (6)
ZRC 38254 (3) 38571 (44), 40974 (20), 42496 (10)
|Known Occurrences:||Indonesia: Sumatra: Jambi Prov.: Sungai Alai, km 19.5 on Muara Bungo – Muara (1 28.72 S 102 18.53 E)|
|Miscellaneous Information||Max Size:||3.49 cm SL|
|pH range:||Typically found among submerged bank vegetation, in near stagnant waters, with pH 4.7-6.8.|
|Etymology:||Latin, falx means scythe, alluding to the continuous curved shape of the broad anal and caudal distal margins of a male in display.
Caudal fin rounded. 
|Locality:||Hari river basin, Muara bungo, Jumbi, Sumatra. |
|Water quality:||pH 5.7/GH0-1/KH0-1/TDS30/ lightbrown water |