Gononemertes australiensis

Gononemertes australiensis is a parasitic ribbon worm. It lives commensally in the ascidian "Pyura pachydermatina" found in the sublittoral waters of the New Zealand. "G. australiensis" was found in specimens of "P. pachydermatina" collected in Sydney harbor. These worms were found specifically in the atrium of "P. pachydermatina".
It is dioecious and has several gonads. Each of its gonads produce several oocytes while the male worms carry testes along its parenchyma. Fertilization is external.