Observations regarding in vitro hatching of Raillietina spp. (Cestoda: Cyclophyllidea) onchosphere

Abstract

The study has been realised in May 2016 having as purpose the observation of the onchosphere hatching process. The eggs of Raillietina spp. were aquired from feces belonging to Great Spotted Woodpecker (Dendrocopos major) that was naturaly infested. Initally, the samples were examined from a parasitological point of view using the Willis method. The egg concentrate has been obtained using the protocol described by VOGE and all. (1961) with some adjustments. The egg suspension was incubated at 30 oC for an hour. The hatching process of the oncosphere has been observed on the slide with the optical microscope (Motic B series) fitted with a Moticam 1000 camera, using the x400 magnification. Measuring has been realised with Motic Images Plus 2.0 software. The temperature of the slide in the moment of examination was 32oC. The whole hatching proces lasted 5 hours and went through the following stages: after half an hour the hexachant embryo has broken the basal membrane and entered the vitelline layer, the onchosphere was vigorously pushing and scraping the granular structure belonging to the vitelline layer, then the vitelline membrane and the egg shell was perforated after four and a half hours, thus completing the actual hatching process. After hatching, the onchosphere engaged in a series of swim-like motions in the liquid mass.