Investigation of the field transcriptome of the calanoid copepod Calanus finmarchicus (Crustacea) during the Arctic Midnight Sun, using RNA sequencing. CV stage individuals were sampled at two stations along a latitudinal gradient, very close to summer solstice. The southern station was located at 74.5 degree N, 30 degree E and was ice-free. The northern station was located at 82.5 degree N, 30.8 degree E and was ice-covered. At each station, samples were performed every 4 hours to cover a complete 24 hours cycle. For each time point and each station, RNA sequencing was performed on 3 replicates of 15 CV stage copepodites pooled.