Duck body condition affects the number of parasites in the gastrointestinal tract, as evaluated with the Akaike information criterion.

The aim of the study was to determine the relationship between the body condition, and the number of parasites in the gastrointestinal tract of the tufted duck (Aythya fuligula), using the Akaike information criterion. Absolute and relative measurements of 197 ducks were taken. Liver mass was positively associated with the number of parasites in the duodenum (ß = 0.5). Heart mass affected positively the number of parasites in the rectum (ß = 2.3), the number of nematodes in the jejunum (ß = 7.45), the total number of trematodes (ß = 1.7), their number in the ceca (ß = 7.3) and rectum (ß = 4.2), and the number of cestodes in the ceca (ß = 8.2). Beak length influenced the number of nematodes in the rectum (ß = 1.7). Left tarsometatarsus length (ß = 1.4) and relative head height (ß = -2.0) affected the number of trematodes in the ceca. Tail length influenced negatively the number of cestodes in the ileum (ß = -0.2). Similarly, a ratio of body mass to body length was negatively associated with the total number of parasites (ß = -0.1), their number in the ceca (ß = -0.2) and rectum (ß = -0.3), the total number of trematodes (ß = -0.3), and their number in the ceca (ß = -0.5) and rectum (ß = -0.4). A ratio of keel-skin length to keel length affected differently the total number of parasites in the ceca (ß = 9.1), the number of nematodes in the jejunum (ß = -17.9) and the number of trematodes in the duodenum (ß = -5.8). A ratio of fat mass to body length affected the number of cestodes in the jejunum (ß = 1.8). The present study indicates some morphological and anatomical parameters that may be useful for determining the correlation between the body condition and the level of parasitic infection.

Redescription of Quasiamidostomum Fulicae (Rudolphi, 1819) Lomakin, 1991 (Nematoda: Amidostomatidae), a Parasite of Fulica Atra (Gruiformes).

INTRODUCTION: Quasiamidostomum fulicae (Rudolphi, 1819) Lomakin, 1991, is a species of which the systematic position is still unclear, and it is reported in the literature under many synonyms. In the present study, an attempt has been made at establishing the ultimate systematic position of Quasiamidostomum fulicae against the backdrop of selected Amidostomatinae species. MATERIAL AND METHODS: The parasites were identified based on measurements of external and internal structures. Ecological analysis of Q. fulicae was carried out using the quantitative indices (frequency, prevalence, mean intensity, relative abundance, and dominance index). Statistical analyses (discriminant analysis) were performed on measurement data. RESULTS: The intestines of 77 coots were examined. They yielded a total of 398 parasites, including 67 identified as Q. fulicae. Both males and females were located in the muscular gizzard. The morphometric analysis of Q. fulicae in this study showed the dimensions of all the internal organs to be in agreement with measurements reported by other authors. The discriminant analysis, used to find the differences between the examined nematode species (Amidostomoides acutum, A. petrovi, A. monodon, Amidostomum anseris, and Quasiamidostomum fulicae), gave highly significant results (P < 0.0001) with respect to both males and females. CONCLUSION: The results justify the separation of Q. fulicae from the genus Amidostomum.

Tetrameres globosa (Linstow, 1879) (Nematoda, Tetrameridae) ­ a nematode of the Eurasian coot Fulica atra (Linnaeus, 1758) recorded for the first time in Poland

During parasitological studies of 23 Eurasian coot Fulica atra (Linnaeus, 1758), 91 nematodes were isolated. Three of them, found in the proventriculus, were identified as Tetrameres globosa (Linstow, 1879). This paper presents the morphological characteristics of the discovered males of T. globosa.

The use of selected statistical methods and Kohonen networks in the revision and redescription of parasites

Revisions and redescriptions of species and higher taxa have been known in parasitology since the first description of a parasite. Usually, they are based on standard morphometric methods or more modern genetic analysis. The former are not always sufficiently reliable, while the latter often require expensive equipment, pre-defined genetic markers, and appropriately prepared research material. They may be replaced by multivariate statistical methods, in particular discriminant analysis and cluster analysis, and Kohonen artificial neural networks included in data mining. This paper presents the examples of specific applications of these methods for the verification of the affinity of nematodes. The discriminant analysis showed that it was possible to statistically significantly discriminate individual nematode species, both for males and females, based on morphometric variables. This confirmed the previously assumed division of the species complex Amidostomum acutum into three distinct species. Similarly, hierarchical cluster analysis, used for the determination of coherent groups of nematode parasites, allowed the identification of relatively homogeneous clusters of nematode species depending on their circle of hosts, and groups of hosts.

Revision of the species complex Amidostomum acutum (Lundahl, 1848) (Nematoda: Amidostomatidae) by use of molecular techniques.

The aim of the work is to confirm the species differentiation of the nematodes of the Amidostomatidae family: Amidostomoides acutum (Lundahl, 1848) Lomakin, 1991; Amidostomoides monodon (Linstow, 1882) Lomakin, 1991, and Amidostomoides petrovi (Shakhtahtinskaya, 1956) Lomakin, 1991, which still are used in the parasitological literature as synonyms of Amidostomum acutum (Lundahl, 1848). The research material consisted of nematodes isolated from gizzards of dabbling ducks from the north-west of Poland. To confirm the species differentiation, DNA from the nematodes was isolated and approximately 630bp of the 28S rRNA gene were sequenced. The obtained DNA sequences were tabulated and then phylogenetic analysis were conducted using the UPGMA method. The results of the research distinctly diversify the nematodes of the genus Amidostomoides at the DNA level, which together with morphological and ecological differences among them (hosts from different systematic groups) enables to classify them into the separate species.