Morphometric studies of Protostrongylidaes third stage larvae (Nematoda: Protostrongylidae) found in Helicella obvia in the pastures of Central South Bulgaria

Silvia Kalcheva, Dian Georgiev and Yanko Yankov

Abstract: The purpose of the current study was to investigate the morphometric characteristics of L3 protostrongylids, found commonly in intermediate hosts in Central South Bulgaria and to reveal the most common intermediate host in the studied region. Three terrestrial snaisls species: Helicella obvia, Zebrina detrita and Monacha cartusiana were collected from pastures primarily used by sheep and goats in the region of Stara Zagora city during the period from March to June and from September to November in 2017. Helicella obvia was the most widely distributed in all studied pastures. The highest general parameters of invasion with protostrongylids were observed in Helicella obvia. A total of 150 larvae of protostrongylids were identified, belonging to the following species: Mullerius capillaris, Neostrongulys linearis and Cystocaulus ocreatus. The established morphometric parameters on L3 of these species were as follows: M. capillaris - average body length 0.624 mm and average length of the tail (the distance between the anal orifice and the tail tip) - 0.038 mm; N. linearis - 0.577 mm and 0.030 mm, respectively; C. ocreatus were 0.676 mm and 0.032 mm, respectively. The seasonal dynamics of the protostrongylids showed that the biggest invasion observed in all investigated pastures was during autumn and spring. The abundance of the nematode`s populations through different sites was low. The most common protostrongylid species was M. capillaris.

Keywords: C. ocreatus; M. capillaris; N. linearis; sheep and goats; snails

Date published: 2020-12-15