chinese on colour but bumps hint jap....did it use to have orange above tail? Pattern and colour of belly may indicate which it is also but i cant memba which is which now ive sold my breeders.
Hard to sex but possible to make a good guess if others to compare to. Need others cos females have a bit of a bulge there aswel, males just bigger. More obvious with age as males get bigger and more defined 2 bumps. Males tail will also go to a point when mature and may get colouration and or stripes on tail when in season.
only need a small tank, i keep 5 that size in a small plastic tank with vented lid. guess 30cm long 20cm wide. I almost need to upsize the tank but thats give you some idea how little room they need. 1 to 2 inch water and bit of driftwood in middle which has a little bit of java growing on. feeding pinhead to small crickets, they eat on land and in the water, just started them on frozen bloodworms, use tweezers to get them use to it, doesnt take much encouragement and soon just drop a cube in.
can co exist but i wouldnt do it, wouldnt want to risk them breeding, not sure if possible tbh.