Predation affects body shape in the knife livebearer Alfaro cultratus (Cyprinodontiformes: Poeciliidae)

• DOI: 10.22541/au.169337393.33997227/v1
• Publication Date: 2023-08-30T05:38:56Z
• Authors: Diego Ardon; Kaitlyn Golden; Trevor Williams; Mark Belk; Jerald Johnson
• Keywords: Poeciliidae; Cyprinodontiformes; Morphometrics

Livebearing fishes are a standard model for studying the effect of predation on prey biology. Numerous studies have found differences in life history, sexual selection, behavior, and morphology between populations same species that co-occur with predators those do not. Alfaro cultratus is livebearing fish different environments, but unlike other livebearers, this also has an extreme body shape laterally compressed. Given unusual morphology, we asked if environment would still predict overall shape, as been documented species. We collected specimens from both predator no-predator sites Costa Rica. used geometric morphometrics analysis to determine affected by while controlling size river gradient. Body does indeed differ environments; however, observed contrast patterns livebearer systems. environments had deeper shorter bodies caudal peduncles than without dominant predators.