That isn't the standard port. Usually the port is 3306
Have you tried including the port in your connection server?
Are you able to see your database from phpMyAdmin? What does it say the server name is on the top of phpMyAdmin when you are looking at the database? Based on the error message I'm guessing the problem is with the server setting in your connection dialog.
What version of php did you have running? If you go to your php_info page (I seem to recall MAMP Pro gives you one) then it should say the version of php and have some basic information about your server installation including your MySQL server port.
If you can't find it, just create a blank page with the code:
And browse that page and it will tell you about the server installation. Make sure you are running a version less than v7 and that mysql is listed as an installed component. Then double check the mysql default port. If it isn't 3306 try including it with your server name in your database connection.