Complex sentence: Freshwater apple snails in the genera "Pomacea" and "Pila" use a siphon to breathe: they breathe air using the siphon while submerged as an anti-predator adaptation, reducing their vulnerability to attacking birds.
Split into simpler sentences: Freshwater apple snails in the genera "Pomacea" and "Pila" use a siphon to breathe. They breathe air using the siphon while submerged; this is an anti-predator adaptation, reducing their vulnerability to attacking birds.