Expand +/- button for taxonomy display in a page
You want to try to use Views Accordion:




  Views Accordion provides a display style plugin for the Views module.
  It will take the results and display them as a JQuery accordion, using
  the first field as the header for the accordion rows.
  
  For Drupal 7 the module integrates the jQuery UI Accordion plugin as a
  views style plugin. You can configure the options provided by the
  jQuery UI plugin.
  
  For Drupal 6 the module used it's own jQuery code, so a different set
  of features is available for D6.


Views can override the default taxonomy pages, or you can try to create your own grouped taxonomy listing which uses this display plugin.