Betta simplex is a small sized mouthbrooder in the picta group. The most common type locality of betta simplex is the krabi province of thaland, but there are many other lesser known localities which creates a bit of a variety meaning the krabi species is possibly smaller or larger thne those from other localities. Features: The most distinguishing feature of betta simplex is its very large head. The males body color is generally light brown to yellow-ish while the females is a yellow-tan color generally marked by fear or breeding stripes. The anal fin of the male features horizontal yellow, blue/green, black, and white stripes(see photo). the tail also features a blue stripe as it almost looks as if the anal fin connects to the tail with the stripes during breeding displays. Sexing: The male simplex is generally more oclorful then the female. the male's gill and throat covers are an iridescent green while the females are white or yellow. the female also does not feature the tail and anal fin stripes that the male does. both male and female have distinctive chin markings extending to the eyes. Breeding and Keeping: Betta simplex prefers an alkaline water between the Ph of 7.0 and 7.5, as they are from limestone pools some mainly the krabi locality prefer a bit of limestone. The temperature must be between 75 and 80 degrees farenheit or they will become stressed. Betta Simplex is very sensitive to water temperature. A pair can happily be kept in a 2.5 gallon tnak minimum tho 5 gallons is prefered. Nothing special must be done to get thme to breed if you keep a pair together. During conditioning a variety of foods may be fed. My fish eat frozen bloodworms, mysis shrimp, brine shrimp, live grindal worms, and live brine shrimp. during spawing the female initiates the embrace but no eggs will fall if the male is not ready. They must also be kept in a low traffic area if not you will have alot of difficulty in getting the male to keep a spawn. after spawning the female picks up most of the eggs and the "tosses" them to the male one by one and if he is too slow to catch them she snaps them up and tries again. spawning may last up to 24 hours. after spawning you will see the males lower jaw extend and he will nto eat during incubation. Betta simplex holds eggs for around 10 days and the female ovulates about every seven so if the female is not removed at least 3 days after spawning she will pester the male to spawn again in seven days and you will lose the first batch. after 10 days the male will release guppy fry sized babies in groups of 20 or less. they can immediately take a viariety of live foods. young males that have spawned for the first time will most likely not carry the eggs for all 10 days and swallow them. other reasons for swallowing eggs includes infertile eggs, diseased eggs, or sometimes no reaosna at all. the above pics are my own and some information is from Goldstein's book Bettas: A complete owner's manual.