Corynosomaacanthocephalans in their paratenic fish hosts in the northern Baltic Sea

Abstract

Summary:Cystacanth stages of three Corynosoma (Acanthocephala) species, C. strumosum and C. semerme, and a new species in the Bothnian Bay, C. magdaleni, were studied in the fourhorn sculpin (Myoxocephalus quadricornis) in 1996-1997. The length of the trunk and proboscis differentiated the three species in the fish. The stability of the Corynosoma infection was studied by comparing the present results with those collected from the same areas (central and coastal) in 1977(central and coastal) in -1982(central and coastal) in (Valtonen, 1983a. As C. magdaleni and C. strumosum were not separated at that time, the joint infections of these two species (called "C. slrumosum") were compared. The stability of infection with C. semerme in the central Bothnian Bay was noticeable (prevalences were 82.9 in earlier period and 81.9 % in later period), while the prevalences of "C. strumosum" in the same areas had decreased (21 and 1 3.5 %, respectively). This is suggested to be due to the disappearance of the marine bull-rout, Myoxocephalus scorpius, from the Bothnian Bay during the 1990s due to an overall decline in salinity throughout the Baltic Sea. In the coastal area Corynosoma infection was clearly lower than in central area in both periods. 1977 (Valtonen, 1983a

Helmintofauna of turbot Scophthalmus maximus (Linnaeus, 1758) from the southern Baltic Sea including new data

“…The morphometric features found with respect to C. semerme correspond to data reported by other authors (Sokolovskaya 1964, Sinisalo andValtonen 2003). Only total body length in all specimens is slightly lower than that proposed by Sokolovskaya (1964).…”

“…semerme is a parasite which has not thus far been noted in turbot from the southern Baltic. The intermediate host for C. semerme is crustaceans, especially isopod Monoporeia affinis (Lindstrom, 1855), fish constitute the paratenic host, while marine mammals -especially seals -are the final hosts; sometimes larvae occur in birds (Petrochenko 1971, Sinisalo and Valtonen 2003, Kennedy 2006). This acanthocephalan is commonly observed in fish and marine mammals, as well as piscivorous birds in other regions (Helle and Valtonen 1980, Valtonen and Helle 1988, Nickol et al 2002, Sinisalo and Valtonen 2003, Kennedy 2006, Kirjušina and Vismanis 2007.…”

“…The intermediate host for C. semerme is crustaceans, especially isopod Monoporeia affinis (Lindstrom, 1855), fish constitute the paratenic host, while marine mammals -especially seals -are the final hosts; sometimes larvae occur in birds (Petrochenko 1971, Sinisalo and Valtonen 2003, Kennedy 2006). This acanthocephalan is commonly observed in fish and marine mammals, as well as piscivorous birds in other regions (Helle and Valtonen 1980, Valtonen and Helle 1988, Nickol et al 2002, Sinisalo and Valtonen 2003, Kennedy 2006, Kirjušina and Vismanis 2007. In the southern Baltic, it has been noted in smelt Osmerus eperlanus (Linnaeus, 1758), flounder Platichthys flesus (Linnaeus, 1758), cod Gadus morhua (Linnaeus, 1758), herring Clupea harengus (Linnaeus, 1758), and in zander Sander lucioperca (Linnaeus, 1758) in the Vistula Lagoon (Markowski 1933, Janiszewska 1938, Studnicka 1965, Rokicki 1975, Rolbiecki 2003.…”

Intestinal helminths of a landlocked ringed seal ( Phoca hispida saimensis ) population in eastern Finland

“…In contrast, C. magdaleni has been described only in the Gulf of St. Lawrence in Canada (Montreuil 1958), in three ringed seals in the Gulf of Finland (Delyamure et al 1980) and also in grey seals (Halichoerus grypus) in the southern Gulf of Bothnia in the Baltic Sea (Nickol et al 2002). Moreover, Sinisalo and Valtonen (2003) found C. magdaleni cystacanths in two fish species in the north-eastern Gulf of Bothnia, in Bothnian Bay. The parasite communities of the oceanic seals also include cestodes, trematodes and nematodes (Dailey 1975).…”

“…The most abundant of the paratenic hosts of Corynosoma species in Bothnian Bay was the four-horn sculpin (Myoxocephalus quadricornis) (Sinisalo and Valtonen 2003), which is also found in Lake Saimaa as a glacial relict (Savolainen 1975). The sculpin, however, is rare in the lake and only occurs in the coldest and deepest basins (Westin 1970), and unfortunately this species was not available for dissection by us.…”