The water taken in through the siphons for food passes through their gills to deliver the oxygen mussels need to survive.
(The water; taken in; ) (The water taken in through the siphons for food; passes; through their gills; to deliver the oxygen mussels need to survive)
The water The water taken in through the siphons for food
taken in passes
through their gills to deliver the oxygen mussels need to survive