Intraspecific Morphological Variation in Free-Living Stages of Strongyloides Papillosus (Nematoda, Strongyloididae) Parasitizing Various Mammal Species

Abstract

Strongyloides papillosus Wedl, 1856 is one of the most widespread nematodes parasitic in domestic animals. This species has been recorded on almost all continents of the planet. It parasitizes the small intestine of rabbits, sheep and cattle. At laboratory conditions, this species can also infect guinea pigs. Morphological variability of S. papillosus in relation to host species has not yet been studied. Our research showed that L1 and L2 of S. papillosus reached their maximum size in all parameters in guinea pigs: for L1 — length and width of the body, length of esophagus and intestine; for L2 — width of body and length of intestine. L3 of S. papillosus had statistically reliable differences in almost all parameters (except the length of intestine) when parasitizing goats and rabbits. For L3 the width of the body and the length of the tail end, we determined differences between S. papillosus infecting rabbits and guinea pigs, and also goats and guinea pigs. Male S. papillosus were observed to have statistically reliable differences in all morphological parameters for goats and rabbits, and also for rabbits and guinea pigs. Practically all measurements (except the length of the tail) were larger for S. papillosus in guinea pigs and goats than those in rabbits. Free-living females statistically differed by larger size in goats and rabbits. The smallest dimensions were determined for all free-living stages of S. papillosus in goats (except males). The largest size in most cases was determined for larval stages of S. papillosus in guinea pigs.

Specifics of the morphological identification of the pathogen of passaluariasis of rabbits

“…The number of parameters proposed by other authors ranged from one to 10, including the total body length of males, the distance from the head to the nerve ring, maximum body width, total length of the esophagus, length and width of the cylindrical esophagus and bulb, distance from the cloaca to the tail end, the length of the narrowed part of the tail, the width of the narrowed part of the tail in the area of the papillary protrusions and the total length of the spicule. Moreover, our data and the results of other authors are somewhat different (Hall, 1916;Skryabin et al, 1960;Gvozdev et al, 1970;Hugot et al, 1983;Frank et al, 2013;Boyko et al, 2019;Gugosyan et al, 2019;Mykhailiutenko et al, 2019). This difference may be due, in our opinion, to the morphological adaptation of pathogens to ever-changing living conditions.…”

Prevalence of gastrointestinal helminths in ruminants in Ukraine: a 5-year meta-analysis

“…to the infective stage takes place in the environment. Animal hosts become infected with infectious larvae when consuming food and water, as well as percutaneously (Boyko et al, 2009(Boyko et al, , 2019Boyko & Brygadyrenko, 2017, 2019a, 2019bKo et al, 2019). Strongyloides papillosus was the most common in Nige-ria (30.2%) (Karshima et al, 2018), which is consistent with the data for Ukraine, where EI = 100%.…”

Morphometric variability of ground beetles Bembidion minimum (Coleoptera, Carabidae): who should change more, males or females?

“…The morphological variability of invertebrates is largely dependent on environmental conditions (Gugosyan et al, 2019;Sowa & Skalski, 2019;Kozak et al, 2020). There are groups of species among beetles in which the larvae grows for a short period, and the imago develops for a long time (e.g.…”

“…Morphometric variability in the population indicates that the variation in body size is the result of morphometric adaptation to the environment (Benítez, 2013;Osman et al, 2015;Kawano, 2016). Changes in the body size and an individual species distribution across the space are parameters that indicate the degree of environmental burden (McGeoch, 1998;Lagisz, 2008;Boyko et al, 2019). Environmental quality and resource food availability influence metabolic activity.…”