Proximate causes of sexual size dimorphism in Colorado pikeminnow, a long-lived cyprinid

Evidence for sexual size dimorphism (SSD) and its possible causes were examined in the endangered Colorado pikeminnow Ptychocheilus lucius, a large, piscivorous, cyprinid endemic to the Colorado River system of North America. Individuals representing 18?24% of the upper Colorado River population were captured, measured, sexed and released in 1999 and 2000. Differing male and female total length-(LT) frequency distributions revealed SSD with females having greater mean and maximum sizes than males. Although both sexes exhibit indeterminate post-maturity growth, growth trajectories differed. The point of trajectory divergence was not established, but slowed male growth might coincide with the onset of maturation....

Categories: Publication; Types: Citation, Journal Citation; Tags: Colorado pikeminnow, Journal of Fish Biology, Ptychocheilus lucius, age at first reproduction, growth rate, All tags... sex ratio, sexual size dimorphism, Fewer tags