 With an increase of competition, this species will switch from a diet rich in plankton, algae, and detritus to one consisting of zooplankton, other invertebrates, the larvae of many species, and plant-associated animals.The main source of competition for "G. holbrooki" seems to be an increase of its own species and other planktivorous species.The main problem with this is, as mentioned before, it will change its diet; this is common even among the juveniles and both sexes of its own species.