The answer is called the basal plate. Hope this helps.
        
             
        
        
        
Answer: I believe the Lateral Lines are made of mechanoreceptors called neuromasts....
I know that hair cells, like the ones inside a human ear, are used as well.
 
        
             
        
        
        
That would be the nervous system.
        
             
        
        
        
If the food is limited to the squirrels then that could impact how well they reproduce which could impact their numbers which therefore could impact the food source for the foxes which eat them. Fewer squirrels means the foxes will slow down on their reproductive numbers as well...they are all linked!