An exploratory methodology has been used to identify genes related to growth of the shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967). Six hundred postlarvae, with an average (±SD) initial weight of 0.022 g (±0.008), were reared for 60 days in salinity 30 g L−1. In the end, the 15 heaviest (>1.2 g) and the 15 lightest (<0.6 g) animals were frozen in liquid nitrogen. A modified differential display reverse transcription-polymerase chain reaction technique was used to generate expression profiles for all individuals. The resulting cDNA from reverse transcription were amplified by pairing 31 arbitrary primers with a reverse primer anchored to the cDNA tails. From the comparison between the expression profiles of the organisms in the two size classes, differences could be pinpointed. Bands of interest were collected, purified, cloned and sequenced. Despite the relatively small number of primers used, the methodology allowed the identification of three genes, not described previously for the investigated species and possibly related to growth. These partial sequences are likely to belong to genes that code for myosin heavy chain, cyclophilin and haemocyanin as revealed through an amino acid similarity search conducted using the blastp on-line tool.