title: A new key character in males of the family Goodeidae (cyprinodontiformes).
authors.forename: J P
authors.initials: JP
authors.lastname: Thurston
authors.forename: R M
authors.initials: RM
authors.lastname: Laws
mesh_terms: D000825:Animal Structures; D000818:Animals; D003532:Cyprinodontiformes / Q000033:anatomy & histology* / Q000145:classification; D008297:Male