Year-end Sale % OFF 
Abstract
The cyprinid fish Gila atraria Girard (Utah chub) is generally considered a sexually monomorphic species. However, prior observations revealed variation in pelvic fin length within populations that appears sexually dimorphic. We measured the relative pelvic fin length of 419 sexually mature Utah chub from 8 different locations to determine the magnitude and generality of this apparent dimorphism. Pelvic fin length in G. atraria differs between sexes by about 10% on average; males have longer pelvic fins than females. The dimorphism is general across all locations, but it is not related to body size. Magnitude of the dimorphism varies by predation environment – the difference between males and females is slightly greater in low predation environments. We find no evidence for an adaptive function for this dimorphism; however, it does provide an efficient mechanism for determining sex without dissection.
Highlights
Utah chub (Gila atraria) is a member of the family Cyprinidae, and is generally considered a sexually monomorphic species [1], other than some temporary dichromatism during the breeding season in which males display a slight gold coloration [2] relative to females
At least two factors could contribute to sexual dimorphism in fin length in Utah chub
If sexual dimorphism in pelvic fin length is due to sexual selection, it is possible that predation environment could affect the degree of dimorphism
Summary
Utah chub (Gila atraria) is a member of the family Cyprinidae, and is generally considered a sexually monomorphic species [1], other than some temporary dichromatism during the breeding season in which males display a slight gold coloration [2] relative to females. In a large sample of Utah chub collected in connection with other work [1], we observed an apparent sexual dimorphism in pelvic fin length. Dimorphism in pelvic fin length has not been reported for any species in the genus Gila. This represents a novel trait with an unknown function. At least two factors could contribute to sexual dimorphism in fin length in Utah chub. If sexual dimorphism in pelvic fin length is due to sexual selection, it is possible that predation environment could affect the degree of dimorphism. A nonadaptive explanation could account for differences in fin
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
