Complex sentence: The fragile file clam can swim slowly and continuously for about 5 minutes at a time by opening and closing its valves and expelling water in a stream from either side of the hinge, a form of jet propulsion.
Split into simpler sentences: The fragile file clam can swim slowly and continuously for about 5 minutes at a time. It does this by opening and closing its valves and expelling water in a stream from either side of the hinge, a form of jet propulsion.