Streptocara formosensis Sugimoto, 1930 (Nematoda: Acuariidae) in wild ducks from the southern coast of the Baltic Sea

Abstract

SummaryAlthough nematofauna of wild ducks in north-western Poland seems to be quite well known, researchers still discover species that are new for the fauna of this region and Europe in general. One of them is Streptocara formosensis Sugimoto, 1930 with distinct ecological specificity (the nematode parasites only ducks wintering in the southern Baltic Sea) and topospecificity (limited to the gizzard). During parasitological research on 1005 wild ducks representing 17 species, 13,333 nematodes were isolated, 360 of which (2.7 %) were identified as Streptocara formosensis Sugimoto, 1930. The distinguishing feature of this species from other nematodes of the genus Streptocara (Railliet, Henry and Sisoff, 1912) is the absence of a collar and a specific arrangement of deirids at the nerve ring. During the study, the nematodes were located only under the stratum corneum of the gizzard, lying down in the form of characteristic white "springs." This is the first observation of this parasite in the nematofauna of Polish wild birds. The nematode was found in 84 (8.35 %) wild ducks representing 7 species: Aythya Marila (Aythyini), Bucephala clangula, Clangula hyemalis, Melanitta nigra, M. fusca, Mergus merganser, Mergellus albellus (Mergini). The highest prevalence (36.7 %) occurred in mergansers; the coefficient of dominance showed that S. formosensis is a subdominant species in B. clangula, C. hyemalis and M. merganser, and a rare species in other hosts. The presence of the parasite in only three out of 157 examined A. marila suggests that the greater scaup is only an accidental host for the nematode.

First Record ofStreptocara formosensis(Nematoda: Acuariidae) from the Chubut Steamerduck,Tachyeres leucocephalus, Endemic to the Patagonian Coast, Southwest Atlantic

“…Streptocara formosensis differs also from S. californica because the latter has a much larger buccal capsule and larger simple tri-pronged deirids (Gibson 1968). We observe slightly differences in some measures of present specimens in relation with those reported previously (Gibson, 1968;Kro ´laczyk et al, 2012). However, those differences could be due to intraspecific variations in different hosts and localities.…”

“…Streptocara formosensis appears to be an anatid specialist, having been reported in a large number of Anseriformes, mostly in the Northern Hemisphere (i.e., Anas platyrhynchos, Aythya marila, Aythya fuligula, Aythya nyroca, Bucephala clangula, Bucephala islandia, Bucephala albeola, Cairina moschata, Clangula hyemalis, Melanitta fusca, Melanitta nigra, Melanitta perspicillata, Mergellus albellus, Mergus merganser, Mergus serrator, Somateria mollissima) (Gibson, 1968;Delacour, 1975;Carboneras, 1992;Kro ´laczyk et al, 2012). Of these, only A. platyrhynchos and C. moschata have been recorded in Argentina (Carboneras, 1992, Agu ¨ero, personal observations).…”

Stomach nematodes of three sympatric species of anatid birds off the coast of Patagonia

“…Streptocara formosensis appears to be a common parasite of anatids. It has been registered in a large number of Anseriformes, most of which are spread over the northern hemisphere (Gibson, 1968; Delacour, 1975; Carboneras, 1992; Królaczyk et al, 2012). However, Agüero & Diaz (2013) enlarged the host and geographical distribution of this parasite by recording it for the first time in T. leucocephalus from South America.…”