part of part_of organ gonad spermathecum an organ of the female reproductive tract in insects, some molluscs, oligochaeta worms and certain other invertebrates and vertebrates.[1] Its purpose is to receive and store sperm from the male, and can sometimes be the site of fertilization when the oocytes are ready.[2] Some species have multiple spermathecae, as seen in earthworms, where four pairs of spermathecae are present. One pair in 6,7,8 and 9 segments. They receive and store the spermatozoa of another earthworm during copulation.[3] They are lined with epithelium and are variable in shape; some are thin, heavily coiled tubes, others are vague outpocketings from the main reproductive tract. It is one of the many variations in sexual reproduction[WP]. an accordion-like tube that contains sperm and is the site of oocyte fertilization. receptaculum seminis seminal receptacle spermatheca spermathecae reproductive structure