Thelycum (Plural: thelyca) is a copulatory organ consisting of modifications of the posterior two, or sometimes three thoracic sternites in female penaeidean shrimps (Such as Asian tiger shrimp, Penaeus monodon) serving as seminal receptacle. It looks like an external pocket on the ventral side of thorax of penaeidean female shrimps. On the other hand, the male copulatory organ of male penaeidean shrimp is petasma.
বাংলা: থেলিকা, থেলিকাম
Thelycum