Mutualist

Pilot fish have a mutualist relationship with sharks. The pilot fish has a dark blue to blackish-silver color and are slightly lighter in color underneath. They have between five and seven dark stripes going from top to bottom. When the fish is excited, these stripes disappear, and three large blue patches appear on its back

Mutualist measures 22″ from the end of tail to the top of the prosoma (Head).  The width is 11″