ABS 2022
Sexual dimorphism in fin size, shape, coloration, and its implications for animal behavior in killifish
Ruel Hanlan, Kasey Brockelsby, Rebecca Fuller. University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, United States

Unpaired fins (i.e., dorsal, and anal fins) are critical to multiple behaviors in fish. One interesting aspect is that males and females use these fins for different behaviors. Males often use the dorsal and anal fins in signaling; males use the anal fins to direct sperm and sometimes clasp the female during spawning; both males and females use the fins for stabilization during swimming. This creates different selection pressures on males and females. Not surprisingly, the dorsal and anal fins are often sexually dimorphic in terms of size, shape, and coloration. Furthermore, the degree of sexual dimorphism can vary among populations and species. Here, I discuss the degree to which males and females differ in dorsal and anal fins, the degree to which this varies among populations and species, and the timing of when these differences emerge in relation to behavior and development.