Checklist of helminth parasites of threatened vertebrate species from Brazil Muniz-Pereira, Luís C. Vieira, Fabiano M. Luque, José L. Zootaxa 2009 2123 1 45 [246,358,1642,1668] Elasmobranchii Pristidae Animalia Pristiformes 26 27 Chordata family    Pterobothrium fragile