Diagnostic DescriptionRead full entry
Dugesiidae with a ciliated pit on either side of the head and with the copulatory apparatus located in the most posterior part of the body, close to the posterior body margin. Testes ventral and prepharyngeal. Small ovaries directly behind the brain. Anterior sections of the oviducts gradually expanding to form a spacious ampulla communicating with the ovary. Finger-shaped, short penis papilla. Penis bulb elongated, consisting of circular muscle, housing an elongate seminal vesicle, which receives the separate openings of the sperm ducts and the secretion of two types of erythrophilic penis glands. Male and common atrium covered by a well-developed layer of circular muscle and a broad, ball-shaped zone of longitudinal muscle, with some of these fibres attaching around the gonopore. Common atrium with a valve-like constriction before communicating with the gonopore. Oviducts separately enter the bursal canal well above the zone of shell glands. Bursal canal covered with layer of circular muscle and communicating with copulatory bursa. Sperm transfer through exchange of spermatophore.