Changes in gene expression are thought to be required for maintaining tissue's proper function under cold stress, but little is known about the role of each tissue in setting the cold tolerance ability in fish. Oreochromis niloticus and Danio rerio are two tropical fishes they differ in their abilities of cold tolerance. In this study, both fishes were exposed to graded cold temperatures, ranging from 28°C to 18°C and 10°C, and the transcriptomes of 8 tissues at each tempeature were sequenced and compared. By characterizing tissue-based gene expression variation between the two fishes we identified some key tissue specific biological processes, which provide a better understating of the typical biological functions of tissues in physiological fitness under cold stress. Overall design: Examination of gene expression of 21 tilapia samples (seven tissues at three temperatures) This submission represents 'tilapia' transcriptome component of study.