We documented the histological structure and annual development of the testis and the process of spermatogenesis in using light microscopy and transmission electron microscopy. The testis was localized at the end of the body and formed a band. Each end of the testis was connected to the body wall and connective tissue and spermatogenic cells, including spermatogonia clusters at the periphery of the connective tissue and interior spermatocytes surrounded by connective tissue. Spermatocytes that were clustered at different stages were transported into the coelomic fluid and developed into sperm, which left the cell clusters and entered the nephridia. Based on the histological characteristics of the testis, we divided the annual development into 5 stages: mature, release, and restingstages. In addition, we observed spermatogenesis in the testis and coelom using both optical and electron microscopy and documented ultrastructural changes in the nucleolus, acrosome, and sperm tail.