Μετάφραση - Πορτογαλικά Βραζιλίας-Λατινικά - Em rio que tem piranha, jacaré nada de costas

Piranha has not a corrispective latin word, so I decided to use the original word (piranha), adding the correct latin ending (-is).
You can use the expression "cum carnivoris piscibus", that is "with carnivorous fishes".