Structural analysis in gonopodium of the genus Poecilia (Cyprinodontiformes: Poeciliidae) on selected species and its implication on taxonomy

Authors: Mario Lucio-Alvarez

Year: 2019

Abstract

The poecilid family is formed by a group of viviparous fishes, where the male’s anal fin is modified into a reproductive system called gonopodium. This modification makes rays 3 to 5 enlarged and formed segments in each ray that may present structures like spines, hooks, claws, serrated areas and more. The gonopodium has been proven useful to identify species like Xiphophorus or Gambusia and therefore it could be useful in the Poecilia genus. The present study will focus on the taxonomical differences within the species of the genus Poecilia mainly P. latipinna, P. velifera P. petenensis, P. mexicana (sulfur and non-sulfur), P. butleri and P. sphenops; its study may be used as an extra tool for the inexperienced on the taxonomy of Poecilia spp. Each gonopodium was cut and processed for a better description of it. Each species has their traits like the number of spines in the serrated area, the number of internal spines, the presence or absence of a membranous hook in ray 3. The number of spines in ray 4p, the spines in ray 5a and the shape of the claw in ray 5p may serve as an useful taxonomic complement.