The brown shrimp, Crangon crangon, has high reproduction rates, is an opportunistic feeder on endo and epibenthic organisms, and is apparently well adapted to variable environmental conditions. Previous studies revealed unusual expression patterns of digestive endopeptidases with high variability between individuals and between seasons. Such a pronounced variability is not common in other decapod species. The reasons for the heterogeneity of digestive enzymes in C. crangon are not yet clear, but it may help to explain the extraordinary performance of C. crangon in a highly variable environment. We established a transcriptome-based expression analysis of anabolic and catabolic digestive key enzymes of C. crangon to compare gene expression rates with enzyme activities. Additionally, detailed sequence analyses will be applied to identify multiple gene products. First results indicate that specific enzymes, particularly trypsin and triacylglycerol lipase, are differentially expressed. Statistical analyses suggest that only a minority of the assayed shrimp exhibit high expression levels of enzyme transcripts, whereas most individuals show low expression rates confirming heterogeneity of digestive enzyme transcription. The strategy of integrated gene expression and protein analyses will elucidate biochemical strategies, which support adaptive physiological processes of C. crangon in a highly variable and seasonally changing environment.