Morphological observations on Retinometra longistylosa (Tseng-Shen, 1932) (Hymenolepididae), with an emphasis on the male copulatory apparatus and comments on the validity of Retinometra Spassky, 1955

The morphology of Retinometra longistylosa (Tseng-Shen, 1932), a parasite o f Anser fabalis (Lath., 1787), recorded for the first time in the territory of Slovakia, has been described. Morphological structures of male distal ducts and their configuration on th e protrusion in proglottides of different age suggest that the dilated port ion of the fully evaginated bottle-shaped unarmed cirrus is embraced by a s pinous male canal ad hoc called praeputium cirri, described for the first t ime. The overall size of the cirrus with praeputium is 102-121 x 44-71 mu m . In 1.2 mm wide proglottides the cirrussac is 2.08 mm long. The stylet is about 1.2 times longer than the cirrus-sac. The funnel-shaped copulatory pa rt of the vagina (61-85 x 44-54 mu m) has a granular internal wall. Further more, the taxonomy of R. longistylosa is discussed in relation to the recen t concept on the genus Cladogynia Baer, 1937.