• It is difficult to tell the sex on younger Koi, it gets easier as they get older.
  • Females tend to have rounder bodies and rounder pectoral fins and their fins tend to be somewhat smaller.
  • Males are sleeker, with more pointed pectoral fins, and their fins tend to be larger.
  • Others claim the colors of males are more brilliant.
  • Older males have a sand paper like raspiness on the gill plates, and some claim you can also feel a roughness if you lick your tongue across the front of the pectoral fin. If you try this let us know!
  • The easiest way is when there is a particularly aggressive male chasing the females, with the proverbial nose up the butt, you look for other males chasing the same now identified females.