title: Retrograde positive contrast urethrocystography of the fish urogenital system.
abstract: The radiological differences between the urinary tract of  Dicentrarchus labrax, Sparus aurata, Tinca tinca, and Cyprinus carpio are shown. In fresh water teleosts the urinary bladder is sigmoid and a short urethra leads to the urinary pore. Genital and anal pores are present. In Sparus aurata the urinary bladder has a globoid shape. In Dicentrarchus labrax the urinary bladder is smaller and elongate. In both marine teleosts a single urogenital pore is visible. Positive contrast was used to survey the urogenital system and evaluate shape and size of the bladder, urethra, ureter, and gonadal ducts. Results demonstrate the morphological variability of the urinary bladder and the craniodorsal entry of the ureters into the bladder. It is envisaged that this work will provide baseline information for further imaging studies for investigating the urogenital morphology and can be applied to identify disorders in fishes. Furthermore, the main interest of this study is that it demonstrates the morphological variability of the lower urinary system that exists between different species of fishes.
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Francesco
authors.identifier: 0000-0003-4846-2581
authors.initials: F
authors.lastname: Macrì
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Annamaria
authors.identifier: 0000-0003-1701-3636
authors.initials: A
authors.lastname: Passantino
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Pugliese
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Simona Di
authors.initials: SD
authors.lastname: Pietro
authors.affiliation: Department of Animal Biology and Marine Ecology, Faculty of Science, University of Messina, 98166 Messina, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Zaccone
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Giorgianni
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Bonfiglio
authors.affiliation: Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
authors.forename: Fabio
authors.identifier: 0000-0003-1805-6347
authors.initials: F
authors.lastname: Marino
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000033:anatomy & histology*; D010473:Perciformes / Q000033:anatomy & histology*; D014566:Urogenital System / Q000033:anatomy & histology; D014567:Urography