The Dojo Loach is an egglayer. I have 2 of them in my 75g tank. They spawn regularly. Spawning always coincides with a large water of 35% or more, followed by addition of water set 2-3 degrees cooler. I think this almost simulates a cool summer rain for the fish.
The tank is heavily planted, and the fish begin their spawning activity by rush up and down the whole length of the tank front. The female leads with the male chasing her about half a fish length behind, his head close against her mid section.
The fish will circle around the side staying together and race back.
After about 5 minutes of this the female will start releasing eggs. The male will chase behind in the same formation as before, dropping clouds of milt over the eggs. This will go on for about 20-30 minutes, after which the fish will then retire to their hideout under the driftwood log.
I have never had any fry because it becomes a caviar feeding frenzy, but im sure that would be possible with a seperate large breeding tank.
These fish need ample space to swim in order to complete a breeding run. 4 foot long is about as small as I would go.
The fish can be sexually differentiated by the more pointed pectoral and tail fin of the male fish. (pointy on the edges where the fin turns on the tail fin). Females have much more rounded fins overall, espescially the pectoral fins. Males grow larger overall in length and height from belly to back, while females will be overall more plump width ways when viewed from the top. Females become quite large when gravid with eggs.
Breeders should be conditioned with high quality high protein foods like frozen or live bloodworms, earthworms, tubifex, and shelled peas.
I dont believe Weather loaches become sexually mature until at least 2 years of age. Mine began spawning at about 2 years old and 5-6 inches of size. They are now 8 and 9 inches each and still growing. I believe they will probably reach a foot in length by 6-7 years of age. Their growth slows dramatically once they reach about 3 years of age and if fed well they will continue to bulk up in width and girth before growing in length. Growth seems to go in spurts.