wrong start file chosen for X11 on osx

my system version is OS X 10.9.5. The first time i ran wireshark, it asked for X11. it should be XQuarts which i had installed but i can not find in applications. So i just chose safari. And now i can run wireshark by using the terminal in XQuarts. But everytime wireshark runs, safari runs. it's kind of annoying. what can i do to disconnect wireshark and safari? all advises are welcomed.