title: Slow-growing
design: Sixteen strains with different genetic backgrounds were applied. Total of three pools and 48 cages were used in our experiment. After 120 days for breeding, the five largest individuals in each cage in the first pool were sampled, and their eyestalks, hepatopancreas and intestines were used to extract total RNA as sample RG_1. Then, in the same way as sample RG_1, the 5 extremely small individuals RNA were extracted as sample SG_1. Similarly, in the second and third pools, samples RG_2, SG_2, RG_3 and SG_3 were obtained respectively. After high-quality RNA was obtained, the libraries were grouped and sequenced using Illumina HiSeqTM 2500