Bull. Eur. Ass. Fish Pathol., 23(4) 2003, 201 Metacercariae of polymorphus Baer, 1827 described in Knipowitshia caucasica in Egirdir Lake, Turkey

Ö. Diler and U. Yıldırım

S.D.Ü. Egirdir Su Ürünleri Fakültesi, Egirdir, Isparta. Turkey.

Abstract During the period from October to December 2001, Bucephalus polymorphus metacercariae were described in a new host, Knipowitshia caucasica from Lake Egirdir. A total of 614 fish were col- lected and the intensity of invasion varied from 10 to 120 parasites per fish. Prevalence of metacercariae of B.polymorphus was 100%, and encysted metacercariae of B.polymorhus were ob- served in the muscle of the host. In spite of the high level of infection with metacercariae, mor- tality was not observed in K. caucasica from the Lake.

Metacercarial infections caused by Bucephalus Knipowitschia caucasica (syn. Pomatoschistus spp (: ) are common in marmoratus), a small member of the Gobiidae fish living in freshwater and estuarine envi- (from 0.8-3.5cm), has been a shallow water ronments (eg. Berrilli and Dezfuli, 2002; inhabitant of Lake Egirdir for the last ten Hoffman,1975; Paperna,1996)). Larval years. In this report, K.caucasica is described bucephalosis due to Bucephalus polymorphus as a new intermediate host of B. polymorphus caused severe epizootics and high mortality metacercariae in Egirdir Lake. of cyprinid fish in the Seine River, France and A total of 614 K.caucasica were collected by Wda River, Poland (De Kinkelin et. al, 1967) hand-nets from the shallow water of Lake and high losses were observed due to an out- Egirdir from October to December 2001. Lake break of the same disease in fish in the Main Egirdir is an oligotrophic lake located in south river, Germany (Hoffmann et. al,1990). An western Turkey. The economically important infestation by B. polymorphus was also inves- fish species of the lake consist of pike-perch tigated in the intestine, pyloric caeca and (Stizostedion lucioperca), carp (Cyprinus carpio) stomach of pike-perch,Stizostedion lucioperca and vimba (Vimba vimba tenella). The pike- in lake Egirdir,Turkey (Yıldırım et. al.1996). perch is the main catch of the local fisherman. In another study, pike-perch was found to be a definitive host for B. polymorphus K.caucasica were transported live to the labo- (Markevich, 1963), but its first intermediate ratory and examined as soon as possible cap- host was Dressenia polymorpha. After leaving ture. Both internal and external organs were the first intermediate host, cercariae pen- thoroughly inspected for parasites according etrated the gill tissue and skin of cyprinids, to standard protocols (Skrjabin,1964; where they encysted as metacercariae Hoffman, 1999) The skin was examined un- (Yıldırım et.al.1996). Bull. Eur. Ass. Fish Pathol., 23(4) 2003, 202

Parasite Host (N) P)revalence (%) I)ntensity (mean Abundance (N* m0ale (314) 160 406.4 1459 f0emale (300) 180 459.8 1496 Table 1. Demographic parameters of infestation by B.polymorphus, metacercariae. N = Total number of host. N* = total number of individual of parasite. der a stereomicroscope.The anatomical and microscopic examination, the metacercariae morphological features of metacercariae were were found in muscles of K. caucasica ( Fig. 4). investigated by light microscopy. The pike-perch, Stizostedion lucioperca was in- For histological examinations, fish bodies troduced to Lake Egirdir in 1955. During sub- were fixed in neutral buffered formalin. The sequent years the pike-perch population in- samples were vacuum-embedded in paraffin, creased substantially while the number of and sagitally sectioned at 6-7 micrometres. cyprinid fishes decreased. However, pike- The sections were stained with H&E. perch catch has declined over more recent years through inadequate availability of food Encysted metacercariae of B. polymorphus and they have became more sensitive to bac- were found in the skin of K caucasica. Preva- terial and parasitic infections (Diler and lence of metacercariae was 100%, and this and Yıldırım 1996, 1997, Yıldırım et al.1996). other demographic data are recorded in Ta- ble1. The intensity of invasion varied from 10 Yıldırım et. al.(1996) investigated the parasitic to 120 metacercariae per host. Bodies of meta- fauna of pike–perch in Lake Egirdir and cercaria were elongated (Fig. 1) with a sucker- B.polymorphus was determined as an en- like rhyncus, with seven tentacular append- doparasite of S. lucoperca. The prevalence of ages and an oral opening in the middle third the parasite ın pike-perch were found to be of body (Fig. 2). The excretory vesicle and in- 54.8% and 100% in 1994 and 1995 respectively, testine were tubular and short respectively. and metacercariae of B.polymorphus were also Metacercarial body length varied between found in the gills and skin of cyprinids. In the 1350 and 1520 micrometres (Fig. 3). During current paper,however, K. caucasica was iden-

Fig1. Numerous oval-shaped metacercariae of B.polymorphus which oval shaped in the skin of Fig2. Anterior appendages of metacercaria (X20). K.caucasica. Bull. Eur. Ass. Fish Pathol., 23(4) 2003, 203

Fig4. Metacercariae of Bucephalus polymorphus in muscle of fish ( X20).

fry (de Kinkelin et.al. 1985). In this study, we observed massive metacercarial infections in Fig3. Elongated metacercariae of B.polymorphus (X4). K. caucasica and large, numerous cysts of B. polymorphus detected in host muscles, but host tified as a new intermediate host for mortality was not observed metacercariae of B.polymorphus in Egirdir Lake. References Berrilli,F., Dezfuli, B.S., (2002). Description of Metacercariae form massive infections in ju- B.anguillae (Trematoda:Bucephalidae) a parasite venile fish and these have been implicated as of the eel Anguilla anguilla from a brackish an important cause of natural mortalities water lagoon of the Adriatic Sea. J. Parasitol. (Paperna,1996). Larvae of B.polymorhus have 88, 382-387 caused high mortality of cyprinid fish (Rutilus Diler, Ö., Yıldırım,M. Z., (1996-1997). A Study rutilus) in the Seine (de Kinkelin, et.al.,1967). on the Parasitic Infection (Bucephalus A similar situation was found in the Main polymorphus Baer, 1827) and Motile Aeromonad Septicaemia in the pike-perch River ( Hoffmann.et.al. 1990) and the latter (Stizostedion lucioperca (L.1758 ) of the Egirdir authors observed high losses due to Lake. Süleyman Demirel University. Journal metacercariae of B. Polymorphus, especially in of Egirdir Fisheries Faculty 5:221-229. cyprinids during a period of a sudden in- De Kinkelin, P.,Besse, P., Jolivet,G., crease in water temperature. Hoffman Tuffery,G.,(1967). Pathogenic effect of the cer- et.al.(1990) stated that eutrophication of the caria of Bucephalus polymorphus water system and overcrowding of fish spe- (Baer,1827)(trematoda, Bucephalidae) on the fish population of Seine basin.Comptes cies may causes outbreaks of parasitosis The Rendus Hebdomadaires Des seances de’l external symptoms of the disease were found Academia Des Sciences Serie D: Sciences to be congestion and haemorrhagie in the Naturelles 19, 2321-2324 mouth and bases of the caudal and anal fins De Kinkelin,P. Besse,P. Tuffery,G.(1968). A re- (de Kinkelin et.al.1968). Septic necrosis of fins cent necrosing disease of fish integuments and of affected fish was also described. Further- fins larval bucephalosis due to Bucephalus more, in experimental infections, cercariae of polymorphus (baer,1827) Bulletin Office Inter- national des Epizooties. 69,1207-1230. B.polymorphus caused muscle necrosis in trout Bull. Eur. Ass. Fish Pathol., 23(4) 2003, 204

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Hoffman, G.L.(1975). Lesions due to Internal Paperna,I.,(1996). Parasites, infections and Helminths of Freshwater Fishes, eds. diseases of fishes in Africa .FAO, CIFA Tech- Ribelin,W.E., Migaki,G., in the Pathology of nical paper 31,220p. Fishes. The University of Wisconsin Press. Skrjabin, K.I and others (1964). Keys to the Hoffman, G.L.(1999). Parasites of North Trematodes of and Man English American Freshwater Fishes. Comstock Pub- Translation, University of Illinois Press, Ur- lishing Associates.Second Edition.201-202 bana, 351p.

Hoffmann,R.W.Körting,W.Fisher- Yıldırım,M.Z., Kara,D., Becer,Z:A. Scherl,T.,Schöfer,W. (1990). An outbreak of (1996).Studies on the Bucephalus polymorphus bucephalosis in fish of the Main river. Baer, 1827 (Trematoidea: Gasterostomata) Angewandte Parasitologie.31,95-99. which were ıdentified in the Pike –Perch of Egirdir Lake. J. Parasitology of Turkey. 20, 105- 112.