Morphometric Analysis of Сapillaria anatis (Nematoda, Capillariidae) from Anas platyrhynchos domesticus

The study presents species-specific morphological traits and metric parameters of mature male and female Сapillaria anatis (Nematoda, Capillariidae) nematodes. The capillariids were obtained by examinations of caeca of 205 domestic ducks (Anas platyrhynchos dom.), reared at poultry farms of Poltava, Sumy and Kyiv Regions of Ukraine. Noted sexual dimorphism was significant by seven morphometric parameters, with measurements of females being larger by 12.40–29.69 % than those of males. In addition to species-specific traits, other diagnostic characters were proposed in male and female С. anatis. In males, such taxonomically important features are morphological specifics of pseudobursa, spicule and ornamentation of spicule sheath. In identification of females, morphology of the vulvar area and eggs in uterus should be considered. Eleven metric parameters are suggested for better differential diagnostics of С. anatis.