0 -> species_4
species_4 -> 0
0 -> species_2
species_2 -> 0
0 -> species_6
species_6 -> 0
0 -> species_3
species_3 -> 0
0 -> species_1
species_1 -> 0
0 -> species_0
species_0 -> 0
0 -> species_5
species_5 -> 0