Kii Province
This species was described from Kii Province, Japan. "Jorunna parva" has subsequently been reported from the Philippines, Tanzania, Papua New Guinea, Seychelles and Réunion but there are some doubts as to whether it is really a species complex. The "Jorunna parva" are concentrated in areas where there is an abundance of food and where resources are easily acquired. They often cling to submerged vegetation and spend majority of the time at the bottom of tropical waters.