Updated project metadata. Updated publication reference for PubMed record(s): 26305468. The accessory gland (AG), an important component of the male reproductive system, enhances the fertility of spermatozoa during male reproduction. Some AG proteins are known to bind to the spermatozoa membrane and affect its function and properties. In this study, we describe, for the first time, a comprehensive catalog of proteins of the AG secreted fluid during the mature phase of the Chinese mitten crab (Eriocheir sinensis). AG secreted proteins were separated by one-dimensional gel electrophoresis and analyzed by reverse phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS).