@article{Yevstafyeva_Melnychuk_Nikiforova_Suprunenko_Korchan_Lokes-Krupka_Nehrebetskyi_Korchan_2018, title={Comparative morphology and biology of nematodes of genus Heterakis (Nematoda, Heterakidae), parasites of the domestic goose (Anser anser) in Ukraine}, volume={9}, url={https://medicine.dp.ua/index.php/med/article/view/433}, DOI={10.15421/021834}, abstractNote={<p>The genus <em>Heterakis</em> Dujardin, 1845 is one of the most widely distributed genera of nematode parasites of domestic and wild birds. Geographically and ecologically predominant species include <em>Heterakis gallinarum</em> Schrank, 1788 and <em>Heterakis dispar</em> Schrank, 1790. Prevalence and occurrence of these nematodes in the domestic goose (<em>Anser anser</em> dom.) depend on their biological and morphological specifics which ensure the highest viability, fast growth and maximum fertility in the host. This study presents the abundance and species composition of nematodes of the genus <em>Heterakis</em> in the domestic goose in Ukraine. Comparative study of morphological and metrical characteristics of <em>H.&nbsp;gallinarum</em> and <em>H.&nbsp;dispar</em> adult females and males is presented. Additional morphometric characteristics are proposed for easier identification of the two species. Stages and periods of embryonic development of <em>H. gallinarum</em> and <em>H. dispar</em> nematodes obtained from domestic geese are established according to morphological and metrical characters. Of the two species, <em>H.&nbsp;dispar</em> is prevalent in domestic geese from Poltava, Kharkiv and Kyiv regions. Abundance index of this species is 9.8 specimens, and intensity of infection index is up to 62 specimens. <em>H. gallinarum</em> is rarer, its abundance index is 1.2&nbsp;specimens and maximum intensity of infection is 30 specimens. Species-specific morphological differences are more distinct in male nematodes in the size and structure of the spicules, lateral wing-like protrusions of pseudobursas, numbers and position of tail papillae. Additional metrical characteristics differ between <em>H.&nbsp;gallinarum</em> and <em>H. dispar</em> nematodes, allowing us to identify not only adult specimens but also eggs. Embryonic development of both species occurs in four morphologically distinct stages: protoplast, blastomere cleavage, formation of first and second stage larvae. Eggs of <em>H. gallinarum</em> nematodes become infectious in eight days at 27 °С, eggs of <em>H.&nbsp;dispar</em> in four days, their viability in laboratory culture is 84.3 ± 0.58 and 91.3 ± 1.53% respectively.</p&gt;}, number={2}, journal={Regulatory Mechanisms in Biosystems}, author={Yevstafyeva, V. A. and Melnychuk, V. V. and NikiforovaО. V. and SuprunenkoК. V. and Korchan, L. N. and Lokes-KrupkaТ. Р. and Nehrebetskyi, I. S. and KorchanN. І.}, year={2018}, month={Apr.}, pages={229-236} }