x1 = species_7
x2 = species_24
x3 = species_25
x4 = species_26
x5 = species_1
x6 = species_5
x7 = species_2
x8 = species_4
x9 = species_6
x10 = species_43
x11 = species_3
x12 = species_12
x13 = species_8
x14 = species_9
x15 = species_15
x16 = species_16
x17 = species_17
x18 = species_18
x19 = species_19
x20 = species_10
x21 = species_11