This how i figured out how much mermaids there were
12 divided by 2=12
l l l l l l l l l l l l l
T T T T T T T T
8+8+8+8=32 2+2+2=6
T=Tails E=Eyes A=Arms
O=Octopus F=Fish M=Mermaids
So if you don't understand i am saying that there is 4 Octopuses,3 Mermaids and 5 Fish