Xiphophorus nigrensis, the polymorphic Abra pygmy swordtail

摘要:

" Xiphophorus nigrensis, commonly known as the El Abra pygmy swordtail, is a species with a very limited distribution in one of North America’s most intriguing and beautiful ichthyological regions. The small fish has been the focus of numerous studies due to its unusual polymorphism in both shape and color. It exhibits three different male morphs and two color morphs. Research into the evolution and fitness of these different morphs has provided valuable insights for geneticists and ethologists. In this article, I summarize the research made on Xiphophorus nigrensis, adding my observations on the beautiful species. "