If it helps, as a kid we always called the smaller ones reddies or reds (as short for red bream) and the bigger ones snapper. Found this quote on Wikipedia that shows I wasn't a unique snowflake: "Australia: cocknies (young smaller than legal size), red bream or pinkies (legal size), squire or squirefish (when bigger), snapper (at full size)"
From: http://en.wikipedia.org/wiki/Australasian_snapper#Regional_variation_in_naming