Crab grows by periodic molting, which is controlled by molt-inhibiting hormone (MIH) and ecdysteroids. Untranslated regions (UTRs) play crucial roles in the posttranscriptional regulation of gene expression. In this study, using crab collected from Changjiang (Yangtze), Huanghe (Yellow), Liaohe, and Yalujiang rivers, 33 haplotypes of the 3ꞌ-UTR of ecdysteroid-regulated protein (ERP) gene were i...