- It is difficult to tell the sex on younger Koi, it gets easier as they get
- 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
- 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.