: male:female is 3:2
Starting with females
Every fish has at least 8 stripes
10 fish with 8 stripes have 80 stripes
There are 6 more stripes
As a male fish has one extra stripe, these 6 stripes must belong to 6 male fish.
So there are 6 males and 4 females.
Therefore the ratio of male to female fish is 3:2.
Starting with males
Now $86=9\times9 + 5$
$=9\times 8+9+5 = 9\times8+14$
$=9\times 7+18+5 = 9\times7+23$
$=9\times 6+27+5 = 9\times6+32=9\times6+8\times 4$
Therefore the ratio of male to female fish is $3:2$.