Wiadomoœci Parazytologiczne 2007, 53(4), 301–308 Copyright© 2007 Polskie Towarzystwo Parazytologiczne

Digenea in chosen populations of freshwater snails in northern and central part of Poland

Elżbieta Żbikowska

Zakład Zoologii Bezkręgowców, Instytut Biologii Ogólnej i Molekularnej, Uniwersytet Mikołaja Kopernika, ul. Gagarina 9, 87−100 Toruń; E−mail: [email protected]

ABSTRACT. Background. The aim of this work was to determine the biodiversity of digenean larvae in the snail populations from various water bodies. Material and methods. Snails under study were collected from 29 reservoirs situated in northern and central part of Poland. During the period 1999−2005 10.581 snails from 6 species (among which two species dominated: stagnalis — 9.469, and corneus — 737 specimens) were examined for shedding cercariae. The total number of 4.404 molluscs was parasitized by 25 species of . The dominant species found were: Diplostomum pseudospathaceum (), Echinoparyphium aconiatum () Pla− giorchis elegans and Opisthioglyphe ranae (Plagiorhiidae) in , while Rubenstrema exasperatum/Neoglyphe locellus (Omphalometridae) and Tylodelphys excavata (Diplostomatidae) in . The adults of the most of Digenea species found in snails were reported from birds.

Key words: cerkariae species, freshwater snails, intermediate host, Lymnaeidae, Planorbidae, Poland.

Introduction or metacercariae [17–19]. There are also some papers concerning the first intermediate host of Digenea have a complicated developmental those parasites. Cecariae of nearly 80 species cycle, in which usually three hosts are involved: were found in molluscs from different part of two intermediate (for some species only one) Poland. Among articles which should be quoted and final host, sometimes additionally separat− are some descriptions of fluke life cycles [20, ed by paratenic host (or hosts). Much data con− 21], the complex studies of parasitic fauna in cerning flukes invasion in vertebrates has been Drużno Lake [22] and works conducted in some known since XVIII and XIX century [1], when reservoirs near Wrocław [23]. In the above most of those parasite species were described. mentioned publications, apart from some cer− Since the discovery of the key−role of snails cariae being identified, the authors mentioned in a fluke life−cycles, the occurrence of these many unidentified ones. Probably the lack of parasites and the prevalence of digenean larvae precise morphological characteristics of cer− in molluscs was studied in many parts of cariae of different Digenea species was the Europe. Some important publications are main cause of a renunciation of studies on known from Ukraine [2, 3], Russia [4–6], prevalence of larval stages of those parasites. Germany [7, 8], Czech Republic [9–12], France Several publications deal with trematodes caus− [13] and Finland [14,15]. ing human and farm ' parasitic diseases. In Poland almost 300 Digenea species were For example in 50s of XX century, the exten− recorded in different host species [16]. Most of sive studies on the Fasciola hepatica larvae in Polish papers concern the occurrence of those populations were carried out parasites in vertebrates — hosts of adult forms in Poland [24]. Nowaday, some fragmentary 302 E. ¯bikowska

Table 1. The characterization of reservoirs under study and infection level of the collected Lymnaeidae and Planorbidae (average prevalence of cercariae were calculted only for L. stagnalis and P. corneus) No. and name of reservoir Stretch Province/district Lymnaeidae Planorbidae (%) [ha] coll/inf/ (%) coll/inf/ (%) Field and meadow reservoirs

1. Jabłonka P. 00.5 W/Konin 325/159 (49)LS — 2. Kwatery P. 03.0 M/Gostynin 262/140 (53)LS 33/15 (45)PC 3. Czarne L. 09.0 M/Gostynin 474/170 (36)LS — 4. Głuchowskie L. 13.7 K−P/Toruń 396/176 (44)LS — 5.Starogrodzkie L. 18.5 K−P/Chełmno 408/169 (41)LS — 6. Tynwałdzkie L. 29.9 W−M/Iława 324/210 (65)LS — 7. Stempa L. 36.1 W/Konin 325/137 (42)LS — 8.Koziegłowskie L. 38.5 W/Konin 318/71 (23)LS — 9. Jeleniec L. 30.4−56.4 K−P/Chełmno 405/179 (44)LS — 10. Wąsoskie L. 58.0 K−P/Nakło 310/83 (27)LS — 11 Zaleskie L.65.0K−P/Tuchola 314/104 LS — (33) 12. Druzno L. 1200−2980 W−M/Elbląg 630/156 (25)LS 149/30 (20)PC 12/1RA 59/14PP; 3/1SN Agricultural — forest reservoirs

13. Deczno L. 43.0 K−P/Świecie 311/90 (29)LS — 14. Górskie L. 43.1 M/Płock 294/108 (37)LS 92/2RA 55/23 (42)PC 15. Sobiejuskie L. 118.0 K−P/Żnin 288/99 (34)LS — 16. Borówno L. 207.7 K−P/Bydgoszcz 280/86 (31)LS — Forest reservoirs

17. Piechota D. 04.0 M/Gostynin 730/419 (57)LS 135/93 (69)PC 18. Pod Zamkiem L 05.0 M/Gostynin 417/181(43)LS — 19. Brzozówka D. 05.0 M/Gostynin 201/85 (42)LS 122/82 (67)PC 20. Sendeń L. 14.2 M/Płock 298/136 (46)LS 75/47 (63)PC 5/1 RA; 1/1SP 4/1SN LS 21. Czarże L. 15.0 K−P/Bydgoszcz 394/176 (45) — 22. Zielone L. 20.2 W−M/Iława 302/112 (37)LS — 23. Soczewka L. 35.5 M/Płock 308/152 (49)LS 61/34 (56)PC 56/32RA; 19/2SP 24. Lubodzież L. 44.0 K−P/Świecie 299/76 (26)LS — Urban and parc reservoirs

25. Aleksandrów P. 00.2 K−P/Aleks. Kuj. 144/81 (56)LS — 26. Osiny P. 01.0 Ł/Kutno 223/143 (64)LS 107/61 (57)PC 27. Jeziorak L. 3460 W−M/Iława 492/260 (53)LS — 28. Bytyń Wielki L 881 Z−P/Wałcz 30/1LS; 70/3RA — 29. Kolbudzkie L. 86 P/Gdańsk 20/3LS — RAZEM 10,581/4,404 coll — collected, inf — infected, % — proportion of infected snails Snails: LS — , PC — , RA — , SP — Stagnicola palustris, PP — Pla− norbis planorbis, SN — Segmentina nitida Province: W — wielkopolskie, M — mazowieckie, K−P — kujawsko−pomorskie, W−M — warmińsko−mazurskie, Ł — łódzkie, Z−P — zachodnio−pomorskie, P — pomorskie. Reservoirs: L. — lake, P. — pond, D. — dam data concerning the Alaria alata occurrence in of this work was to study the Digenea biodiver− Planorbidae [25], and bird schistosomes in sity in common snail species living in some Lymnaeidae [26] were published. reservoirs in northern and central part of Considering a scarcity of information on Poland. The snails collected represented 6 trematode occurrence in a first intermediate species, with the great prevalence of L. stag− host populations in Polish lakes, the main aim nalis, resulted from the inclusion the great num− Digenea in snails 303

Table 2. The trematode species in regularly studied populations of L. stagnalis and P. corneus Parasite species Snail species % of infected snails* Diplostomum pseudospathaceum Niewiadomska, 1984 L. stagnalis 24% Echinoparyphium aconiatum Dietz, 1909 L. stagnalis 23% elegans (Rudolphi, 1802) L. stagnalis 21% Opisthioglyphe ranae (Frölich, 1791) L. stagnalis 10% revolutum (Frölich, 1802) L. stagnalis 03% Sanguinicola inermis Plehn, 1905 L. stagnalis 02% Plagiorchis maculosus (Rudolphi, 1802) L. stagnalis 02% conoideum (Bloch, 1782) L. stagnalis 01% Notocotylus attenuatus Luhe, 1909 L. stagnalis 01% Tyleodelphys clavata (Nordmann, 1832) L. stagnalis 01% Trichobilharzia szidati (Odening, 1996) L. stagnalis < 1% Apatemon burti (Miller, 1923) L. stagnalis < 1% Neoglyphe sobolevi Shaldybin, 1953 L. stagnalis < 1% Unidentified: metacerkariae, sporocysts and/ or rediae L. stagnalis 09% Rubenstrema exasperatum (Rudolphi, 1819) P. corneus 07% / Neoglyphe locellus (Kossak, 1910) Tyleodelphys excavata (Rudolphi, 1819) P. corneus 06% Bilharziella polonica (Kowalewski, 1895) P. corneus 02% Notocotylus ephemera (Nitzsch, 1807) P. corneus 02% Echinostoma spiniferum (La Valette, 1855) P. corneus 02% Haematoloechus asper (Looss, 1899) P. corneus 01% Rubenstrema opisthovitellinum Sołtys, 1954 P. corneus 01% Unidentified: metacerkariae, sporocysts and/ or rediae P. corneus 79% *the total number of infected Lymnaea stagnalis Σ = 3956, Planorbarius corneus Σ = 385 ber of these snails, collected prior to this study 59 — P. planorbis, 25 — S. palustris and 7 — for investigations of snail−trematode interac− S. nitida specimens (Table 1). tions [27]. The presence of cercariae was checked by placing a snail in a small amount of tap water Material and methods under a light source for 2–24 h. In such condi− tions, cercariae left their host. Digenean species Snails were sampled during 1999–2005 peri− were identified on the basis of morphological od in the near−shore zone of 29 reservoirs features, according to Nasincova [9] and (Table 1). The individuals of Lymnaea stagnalis Niewiadomska et al. [15]. The individuals (L.) were sampled regularly (once a month from which failed to release cercariae were dissected April to October during two vegetation periods) to find other digenean stages (sporocysts, redi− from 27 reserviors, and occasionally (single ae, metacercariae). The average prevalence of samples) from 2 other ones. In the eight reser− infected snails (by all trematode larvae) was voirs, during one vegetation period, specimens calculated. of Planorbarius corneus (L.) were also regular− ly collected. The collection of all other snail Results species was restrained to single samples. The Radix auricularia (L.) were collected in four In regularly examined L. stagnalis popula− lakes, Stagnicola palustris (O.F. Muller, 1774) tions the average prevalence of infected snails and Segmentina nitida (O.F. Muller, 1774) — in was various — from 23% in Koziegłowskie two, and Planorbis planorbis (L.) — only in Lake (No. 8), to 65% in Tynwałdzkie Lake one lake. In total ten thousand and five hundred (No.6). Similar prevalence was noted in P. eighty−one snails were collected in 29 reser− corneus populations — from 20% in Drużno voirs under study: 9.469 L. stagnalis individu− Lake (No.12), to 69% in Piechota Dam (No. als, 737 — P. corneus, 230 — R. auricularia, 17). In the smallest reservoirs the percentage of 304 E. ¯bikowska 2 6 71 3 13 * 0 0 0 0 1 11 8 4 2 4 0 <1 0 0 0 0 81916 0 721 14 1 2 1 6 0 0 0 0 0 9 3 7<1 0 0 0 1 723 1 2 0 0 0 0 00 91313 4 3 1<1 71112102616 4 1<1<1 4 1<1 0 0 0 0 0 0 0 0 0 411 0 914 41242 2 0 0 0 5 110 9 2 91512 51 1 31 11 0 0 0 0 0 0 0 0 0 9 1 2 8 1<1 2 3 3 9 1416111011 0 0 0 0 0 0 0 0 0 71414 8 414 0 0 0 6 5 0 0 2 1 1 20141 14 7 5 0 0 0 0 0 415151299 220 6 1 1 0 0 0 0 0 9 1 61110121113 6 8 1 0 0 0 0 0 0 126 2 1 7 0 0 0 0 9 812 7 3<1 0 0 0 0 1 9 4 2<14 <1 1<1 5 <1 43 11 0 0 0 0 0 0 321 1 8 13 8710 12612 10 14 1 1 0 0 0 0 0 0 0 6 7 6 8 5 3<1 <1 2 2<1 3 0 0 0 0 39 12 0 0 0 0 0 4 0 811 5 4 0 0 0 6 7 3 5 0 0 0 0 9131314 8 61010 5 4 3 0 0 0 3 0 0 1 0 4 11211 31321 1 100 26 270 22 0 1 <1 0 <1 3<1 1234567891011121314151617181920212223242526272829 3912 32 12 4135 5011 28 52 37 11 4532 22 2110 34 31 24 13 29 3642 51 41 22 31 24 40 22 21 39 41 25 20 37 17 31 20 38 12 40 48 33 11 23 29 21 35 20 53 32 99 2011 92 59 210 37 19 17 30 41 22 35 37 68 28 38 34 40 36 22 29 31 30 48 37 44 35 31 71 28 35 17 11 42 81 13 12

sobolevi pseudospathaceum aconiatum elegans Digenea speciesDiplostomum Number of reservoir (according to Table 1), number (top) Echinoparyphium and percentage (bottom) of snails with patent invasion Plagiorchis Opisthioglyphe Echinostoma revolutum Plagiorchis Sanguinicola Notocotylus attenuatus Tylodelphys clavata Apatemon Trichobilharzia Neoglyphe ranae maculosus inermis burti szidati Table 3. Digenea Table species in snail populations under study

Snail stagnalis L. Digenea in snails 305 6 6 0 0 * 1 1 33 54 5 0 0 0 0 0 0 * 1 1 * 9 0 0 0 0 0 1 1 3 2 11 12 0 0 0 0 14 2 2 3 2 0 0 0 0 S.n. — Segmentina nitida , 2 4 7 2 0 0 0 0 1 1 * 2 5 3 2 1 715 525 4 3 5 1 1 * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P.p — Planorbis planorbis P.p , S.p. — Stagnicola palustris , R.a. — Radix auricularia

N. locellus

anceps spiniferum Trichobilharzia Sanguinicola Moliniella Echinostoma Notocotylus Bilharziella Tylodelphys Haematoloechus Rubenstrema R. exasperatum) Echinoparyphium Parastrigea * very low number of the examined snails (<20 specimens) for explanation: inermis ephemera polonica excavata asper opisthovitellinum recurvatum robusta franki /

R. a. a. R. p S. corneus P. P.p n. S. 306 E. ¯bikowska infected snails was rather high (Table 1, No.: 1, stagnalis populations examined in the period of 2, 17, 25, 26). 20 years observed 7 trematode species, and Twenty five parasite species were found, as Finnish authors [14] — 11 parasite species in well as unidentified metacercarie, sporocysts two lymnaeids. and/or rediae with immature cercariae. The list The regular two−year examination of L. stag− of identified Digenea species and their preva− nalis enlarged the probability of finding a lence in snail populations are presented in majority of trematode species of these snails Tables 2 and 3. occurring in water reservoirs under study. In L. stagnalis populations four parasite Different trematodes can have different maxi− species were noted most frequently: Echino− mum of cercariae shedding from snail−host dur− paryphium aconiatum (in 27 from 29 reser− ing season [27]. It is worth to emphasize that voirs), (25/29), Diplosto− only mature (emerged) larvae can be identified, mum pseudospathaceum (24/29), and Opisthio− therefore regular sampling snail populations in glyphe ranae (22/29). Those species composed this kind of study is very important. Moreover, a majority of digeneans (78%) in 27 regularly long lasting maintenance of cercariae non−shed− studied L. stagnalis populations (Table 2). The ding snails in the laboratory is very helpful, as larvae of Echinostoma revolutum, Plagiorchis after some time at least some of them could maculosus and Sanguinicola inermis were shed cercariae. observed at least in 10 from 29 water bodies It is difficult to compare the presented data under study. The remaining parasites were with those of Wiśniewski [22] and Bertman and rarely found. Wojciechowska [23], because the authors In the eight P. corneus populations under placed among identified, also many unidenti− study 7 or 8 cercariae species were recognized. fied cercariae. The taxa which were found both Among them Rubenstrema exasperatum by the cited authors, and nowadays belong to: /Neoglyphe locellus, Bilharziella polonica and E. recurvatum in Planorbis planorbis, Cercaria Notocotylus ephemera were noted in three echinata (E. aconiatum), E. revolutum and T. reservoirs, Tyleodelphys excavata and clavata in L. stagnalis, B. polonica and T. exca− Echinostoma spiniferum — in two, and other vata in Planorbarius corneus. Nevertheless, the species only in one of them. It should be long list of both identified and unidentified cer− emphasized that only 21% of snails from these cariae species in snails under study supported populations released cercariae (Table 2). the opinion about high biodiversity of trema− In four snail species (R. auricularia, P. todes in Polish freshwater molluscs. planorbis, S. nitida and S. palustris) five trema− A comparatively high number of Digenea todes were found — S. inermis, Trichobilharzia species in L. stagnalis and P. corneus supports franki, Echinoparyphium recurvatum, Moliniel− the data of the authors who maintain that big− la anceps and Parastrigea robusta. (Table 3). size snails are very useful in life cycle of those parasites [28]. On the other hand, low trema− Discussion tode frequency in the examined P. planorbis or S. nitida does not result from small body size of The biodiversity of Digenea in snail popula− snails but probably from low snail sampling. tions under study was rather high. In the only In Poland, bird parasites constitute nearly six snail species (where two of them were regu− 50% of known parasitic platyhelminthes [16]. larly collected) 25 Digenea taxa were found. Also in molluscs under study bird flukes domi− For example Faltynkova and Haas [8] described nated. Probably the low specificity to final host 29 different cercariae in 26 snail species from species and high mobility of birds created very 26 localities, and in another study Faltynkova useful conditions for the parasite spreading in [12] found 27 Digenea taxa in 12 molluscs the environment. species. Also Loy and Haas [7] in several L. The domination of D. pseudospathaceum, E. Digenea in snails 307 aconiatum and P. elegans in L. stagnalis veri− stomatidae). Trudy Astrachanskogo Zapovednika 9: fied the data of different researchers of 64–104. European snail populations. In twenty−year [6] Ginecinskaja T.A., Dobrovol'skij A.A. 1964. K faunie licinok trematod presnovodnych molljuskov delty study of German reservoirs Loy and Haas [7] Volgi. III. Furkocerkarii (sem. Cyathocotylidae) i sti− observed high prevalence of Diplostomum letnyje cerkarii (Xiphidiocercariae). Trudy Astra− spathaceum (: D. pseudospathaceum) chanskogo Zapovednika 11: 29–95. and Pseudoechinoparyphium echinatum (syn− [7] Loy C., Haas W. 2001. Prevalence of cercariae from onym: E. aconiatum) in L. stagnalis, and Lymnaea stagnalis snails in a pond system in Sou− thern Germany. Parasitology Research 87: 878–882. Vayrynen et al. [14] noted high percentage of [8] Faltynkova A., Hass W. 2006. Larval trematodes in snails infected with P. elegans larvae. freshwater molluscs from the Elbe to Danube (Sou− In the eight P. corneus populations, only theast Germany): before and today. Parasitology Re− 21% snails shed cercariae. This fact constitutes search 99: 572–582. very serious obstacle in comparing different [9] Nasincova V. 1992. Vyvojove stadia motolic v nasich vodnich plzich a vyvojove cykly vybranych druhu ce− trematode species contribution in the parasite ledi Omphalometridae and Echinostomatidae. Ph.D. communities in snails. Thesis, UCAV Ceske Budejovice. The studies of trematode prevalence in snail [10] Kolarova L., Horak P., Fajfrlik K. 1992. Cercariae of populations will be continued. Other mollusc Trichobilharzia szidati Neuhaus, 1952 (: species will be examined. The regular snail sam− Schistosomatidae): The causative agent of cercarial dermatitis in Bohemia and Moravia. Folia Parasitolo− pling in environment and maintenance of cer− gica 36: 399–400. cariae non−shedding individuals for a long time [11] Horak P., Kolarova L., Dvorak J. 1998. Trichobilha− in a laboratory will make the list of Digenea rzia regenti n.sp. (Schistosomatidae, Bilharziellinae), species in snails living in our country longer. a new nasal schistosome from Europe. Parasite 5: 349–357. [12] Faltynkova A. 2005. Larval trematodes (Digenea) in Acknowledgements molluscs from small water bodies near Ceske Budejo− vice, Czech Republic. Acta Parasitologica 50: 49–55. I would like to thank Mrs.Mrs. J. Flasińska, A. Łapkie− [13] Ferte H., Depaquit J., Carre S., Villena I., Leger N. wicz,, K. Kwiatkowska, E. Sroczyńska, A. Śpiąkowska, K. 2005. Presence of Trichobilharzia szidati in Lymnaea Ziemniarska, I. Żulewska and Mr. Mr. M. Kostkiewicz and stagnalis and T. franki in Radix auricularia in northe− P. Suchocki — former students in Departament of astern France: molecular evidence. Parasitology Re− Invertebrate Zoology at Nicolaus Copernicus University in search 95: 150–154. Toruń, for their help in collecting the snails and isolating [14] Vayrynen T., Siddall R., Valtonen E.T., Taskinen J. cercariae. I am most grateful to Mrs. J. Rudolfova from 2000. Patterns of trematode in lymnaeid Schistosome Group at Charles University in Prague for snails from northern and central Finland. 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