October 30 2019
12:00 LSB 2320
Biological Sciences Department, California Polytechnic State University, San Luis Obispo
The Role of Sexual Selection in Maintaining Color Polymorphism in a Cuban Poeciliid Fish
Color polymorphism is an important contributor to biological diversity, and the persistence of multiple morphs within a site requires evolutionary explanations. Girardinus metallicus is an endemic Cuban poeciliid fish that exhibits male-specific melanin polymorphism throughout its range. The wild type “plain morph” males are common, whereas the melanic “black morph males” are rare, a pattern seen in other fishes in this family. However, unlike in those species, black morph male G. metallicus perform a distinctive display during mating that is not observed in the wild type males. Our lab uses student-driven studies to investigate the selection pressures important in maintaining this polymorphism, such as negative frequency dependent sexual selection. We also investigate the role of the black morph display, which had been thought to be courtship but may function as aggressive mate guarding. I will describe our results to date and also address plans for future studies of phenotypic correlates of these and a recently discovered, extremely rare third morph, to address the persistence of the polymorphism.
Host: Greg Grether