Integration between swim speed and mouth size evolves repeatedly in Trinidadian guppies and aligns with suction-feeding fishes.

Well-supported correlations between swim speed and mouth size during prey capture suggest the broad existence of an integrated relationship between locomotion and feeding in suction-feeding fishes. However, the influence of specialization on this relationship is unclear. We used divergent populations of Trinidadian guppies () to test whether integration during suction is generalizable to a non-suction specialist and whether intraspecific specialization of component systems affects their integration.