x1 = species_1
x2 = species_2
x3 = species_3
x4 = species_4
x5 = species_5
x6 = species_6
x7 = species_7
x8 = species_8
x9 = species_9
x10 = species_10
x11 = species_11
x12 = species_12
x13 = species_13
x14 = species_14
x15 = species_15
x16 = species_16
x17 = species_17
x18 = species_18
x19 = species_19
x20 = species_20
x21 = species_21
x22 = species_22
x23 = species_23
x24 = species_24
x25 = species_25
x26 = species_26