Plagiorchidae Lühe, 1901

Korol, E. N., Varodi, E. I., Kornyushin, V. V. & Malega, A. M., 2016, Helminths Of Wild Predatory Mammals (Mammalia, Carnivora) Of Ukraine. Trematodes, Vestnik Zoologii 50 (4), pp. 301-308 : 303-306

Family Plagiorchidae Lühe, 1901

11. Plagiorchis elegans (Rudolphi, 1802)

H o s t s a n d d i s t r i b u t i o n.

Definitive hosts: L. lutra : P — 33.3 %, I — 11, A — 3.67 (Zhytomyr Region).

In addition to wild carnivorans examined, we found the trematode Metorchis albidus (Braun, 1883) in domestic cat in Sumy Region (1 host infected, out of 6 studied); A. alata , A. donicus and E. perfoliatus were collected from domestic dog.

Generally, trematodes were not very common in carnivorans, comparing to cestodes and nematodes. The overall prevalence of trematode infection in 260 examined host specimens was 39.6 % ( table 1).

In our studies, separate regions of Ukraine were not equally investigated. The largest part of the material was collected in the Polissya (forest) region. Six species of trematodes were registered there, and all those species were found in Kyiv Region . In other regions of Polissya, just 1 or 2 trematode species were found. Six species of trematodes were found in regions close to the Dnieper River (Cherkasy, Poltava, Kherson Regions); and only one species was registered in Crimea .

The trematode A. alata appeared to be the most widespread in Ukraine; it was registered in 9 Regions and in Crimea. Four species of the family Canidae : the red fox, wolf, raccoon dog and jackal harboured this parasite. High prevalence and intensity of infection were observed in the former three hosts. Apparently, all of them successfully support the transmission of this parasite in natural ecosystems. The raccoon dog is the most suitable host for A. alata due to its ecological particularities, such as food preferences ( figs 1 , 2 ). The role of the jackal in the transmission of A. alata in the ecosystems of southern Ukraine is yet undefined, since only 1 host specimen was investigated. We identified two species of the family Mustelidae as paratenic hosts of A. alata .

The trematode I. melis also has comparatively wide host range; it was found in 5 canids and mustelids in 4 regions of Ukraine (Kyiv, Chernihiv, Lviv, Cherkasy Regions). E. perfoliatus in Rivne, Kyiv and Poltava Regions, and A. donicus in Kyiv Region were each registered in 4 species of the hosts, canids and mustelids. P. skworzowi was found in only 2 species of canids in Kyiv Region, and P. truncatum parasitised 2 mustelid species in Zhytomyr and Kyiv Regions.

Co-infection of a single individual host by various species of trematodes was rather rare. The following combinations of species were noted. Four species of trematodes were simultaneously observed in the fox: A. alata + E. perfoliatus + M. skworzowi + A. donicum and in the raccoon dog: A. alata + M. skworzowi + A. donicum + I. melis ; each of the simultaneous infections was registered only once. Co-infection with three species of trematodes was observed in the fox ( A. alata + S. denticulatum + M. appendiculatus ) and in the American mink: ( P. truncatum + I. melis + A. donicus ). Two species of trematodes in a single host individual were found more frequently. There were combinations of the following: A. alata + A. donicus (in two foxes), A. alata + E. perfoliatus (in one fox and in two raccoon dogs), A. alata + I. melis (in one fox and in two raccoon dogs), A. alata + Ph. cordatum (in one fox), E. melis + A. donicum (in two raccoon dogs), P. truncatum + I. melis (in one American mink), P. truncatum + P. elegans (in one otter), E. perfoliatus + I. donicum (in one otter). In general, 7 out of 64 examined foxes (10.9 %) harboured more than one trematode species. Trematode co-infection with different species was common in raccoon dogs: 7 out of 10 specimens examined (70 %). There, the occurrence of two or three trematode species was rather a rule than an exception.

Prevalence % Intensity 100 80 60 40 20 0 0 50 100 150 200

Usually (in 60 examined hosts) trematodes were met in association with others helminths, nematodes and cestodes. Eleven animals were found to be infected with trematodes only.

Wild carnivorans of the Canidae family were the most numerous among the hosts examined; we studied 166 foxes, 32 wolves and 14 raccoon dogs. In foxes, the prevalence of trematode infection reached 38.6 %; 9 species of trematodes were found in these hosts. A. alata was a dominant species in trematode communities of the red fox in Ukraine, with infection prevalence 38.55 % and mean intensity 97 ( fig. 1 ). All other trematode species were found in smaller number of host individuals (1–3), infection prevalence was 0.6–1.81 %. The mean infection intensity in those species varied widely, from 1.3 up to 154. Most trematodes found in the red fox ( E. perfoliatus , M. appendiculatus , M. skworzowi , S. denticulata , Ph. cordatum ) are rare parasites of this host under the conditions of Ukraine (mean intensity was about 10). The remaining 2 species, I. melis (mean intensity 3.5) and A. donicus (mean intensity 1.3) are occasional parasites of the host. To date, 14 species of trematodes were registered in foxes in Ukraine, considering the previously published data (table 2).

In the racoon dog, the prevalence of trematode infection was 71.4 %. Five species of trematodes were found ( fig. 2 ). As in the red fox, A. alata predominated (P = 42.86 %, mean intensity 667). The other 4 species had similar occurrence (P = 14.29 %), though M. skworzowi was prominent due to comparatively high mean intensity, 256.5. In E. perfoliatus , the mean intensity was 14.5. These two species may be considered as common parasites of the raccoon dog. E. melis and A. donicum were rare parasites of the host; their mean intensity did not exceed 1–3.5.

Prevalence of trematode infection in the wolf was somewhat lower, 34.4 %. A. alata is the only species of trematodes registered in the wolf in Ukraine. Some other species of trematodes (table 2) were rarely recorded on the territory of the former USSR ( Kozlov, 1977): O. felineus , P. truncatum , M. yokogawai , and P. truncatum . In the present study, the latter species was found only in the weasel. Apparently the trematode community in the wolf is depauperated due to feeding preferences of the host, whereas the infection with A. alata is ensured by the participation of paratenic hosts, including mustelids, in the transmission.

The only trematode species found in the jackal in the present study was A. alata . Two more species were recorded in this host in the former USSR: Dexiogonimus ciureanus and P. elegans ( Kozlov, 1977) .

Prevalence % Intensity 100 80 60 40 20 0 0 200 400 600 800

The distribution of trematode parasites among canid hosts is presented in table 2.

Our data on trematode infection in Mustelidae are not comprehensive, since only 40 specimens of 8 species were investigated. Eight species of trematodes were found in 5 host species. Four of them parasitised the American mink and the otter, 2 species were found in the weasel; the stone marten and polecat each harboured one species. Two trematode species, P. truncatum and P. elegans , were specific to mustelid hosts. The former parasite is known also from wild canids in neighbouring regions, and the latter one is an occasional parasite of predatory mammals. The other 6 species are common in other carnivorans in Ukraine. According to the literature ( Iskova et al., 1995), two more species, T. acutum and E. squamula , were registered in the mustelids in the Carpathian Mountains and both are likely specific parasites of these mammals. Mesocercariae of A. alata were found in 2 species of mustelids.

Trematodes of mustelids, unlike the cestodes, do not exhibit a narrow specificity to definitive hosts. However, mustelids are apparently more suitable hosts for I. melis , P. truncatum , and probably, A. donicum , as evidenced by higher intensity of infection in this group of hosts.

Information on trematode parasites found in each separate carnivore species is summarised in the list below.

W o l f: 1. Alaria alata .

Fox: 1. Alaria alata , 2. Pharyngostomum cordatum , 3. Mesostephanus appendiculatus , 4. M. skworzowi , 5. Isthmiophora melis , 6. Echinochasmus perfoliatus , 7. Stepanoprora denticulata , 8. Apophallus donicus , 9. Ascocotyle italica .

Racoon dog: 1. Alaria alata , 2. Mesostephanus skworzowi , 3. Isthmiophora melis , 4. Echinochasmus perfoliatus , 5. Apophallus donicus .

J a c k a l: 1. Alaria alata .

Otter: 1. Echinochasmus perfoliatus , 2. Pseudamphistomum truncatum , 3. Plagiorchis elegans , 4. Apophallus donicus .

S t o n e m a r t e n: 1. Isthmiophora melis .

Weasel: 1. Alaria alata , 2. Isthmiophora melis .

P o l e c a t: 1. Alaria alata .

American mink: 1. Isthmiophora melis , 2. Echinochasmus perfoliatus , 3. Pseudamphistomum truncatum , 4. Apophallus donicus .

Figures

Fig. 1. Structure of the trematode fauna of the red fox in Ukraine (original data): ALT — A. alata; EPE — E. perfoliatus; ADO — A. donicum; SDE — S. denticulata; MAP — M. appendiculatus; PCO — Ph. cordatum; MSK — M. skworzowi; IME — I. melis.

Fig. 2. Structure of the trematode fauna of the racoon dog in Ukraine (original data): ALT — A. alata; MSK — M. skworzowi; EPE — E. perfoliatus; IME — I. melis; ADO — A. donicum.