Cake's naming conventions can be really nice - you can name your model Box, your controller Boxes, and everything just works out. There are occasions (especially for our non-english speaking friends) where you may run into situations where Cake's inflector (the class that pluralizes, singularizes, camelCases, and under_scores) might not work as you'd like. If Cake won't recognize your Foci or Fish, editing the custom inflections configuration file is where you'll need to go.
Found at /app/config/inflections.php is a list of Cake variables you can use to adjust the pluralization, singularization of classnames in Cake, along with definining terms that shouldn't be inflected at all (like Fish and Deer, for you outdoorsman cakers) along with irregularities.
Follow the notes inside the file to make adjustments, or use the examples in the file by uncommenting them. You may need to know a little regex before diving in.