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In total, 400 bony fishes of 32 species (7 families) were examined. Acanthocephalans occurred in 55 host specimens of 15 species. Five species were recognised, including 3 echinorhynchid species maturing in fish, Metacanthocephalus campbelli (Leiper et Atkinson, 1914), M. dalmori Zdzitowiecki, 1983 and Echinorhynchuspetrotschenkoi (Rodjuk, 1984), as well as cystacanths of 2 polymorphid species maturing in seals, Corynosoma bullosum (Linstow, 1892) and C. pseudohamanni Zdzitowiecki, 1984. All species were found in fish in the Weddell Sea for the first time. M. dalmori, E. petrotschenkoi and C. bullosum were not previously recorded in the high Antarctic. Out of 26 host/parasite relationships, 24 are new. The level of infection was very low. Only 114 acanthocephalan specimens were found, with the maximum intensity of 12 cystacanths in one Trematomus pennelli. C. bullosum was the most abundant species (53% of all specimens). Out of 11 fish species examined in numbers of 18-46 specimens, only 6 were infected. Trematomus scotti was the most strongly infected - prevalence 54%, relative density 1.04.
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Among 544 species of helminths recorded in birds on the territory of Poland, probably some (17 species of Digenea, 21 Cestoda, 13 Nematoda and 5 Acanthocephala) do not belong to the native fauna. These are helminths obtained in mature stage from birds shortly after their arrival from wintering grounds, or from foreign populations wintering with us, or being in the course of spring or autumn migration through the area of our country. In general, these helminth species have been recorded sporadically in the examined birds.
Paratenuisentis ambiguus, an acanthocephalan originating from North America, is an alien species parasitising the European eel Anguilla anguilla. It was first recorded in Lake Łebsko, on the central coast of Poland. The report gives morphometric measurements of male and female P. ambiguus from this locality. Because of the spread of the intermediate host Gammarus tigrinus and the appearance of new adults in eels along the southern Baltic Coast, P. ambiguus is evidently able to complete its life cycle in Baltic coastal waters.
New data on the infection with Acanthocephala of 33 fish caught in Admiralty Bay in November 2007 to January 2008 are given. These fish belong to 5 species: Notothenia rossii (22 immature specimens), Lindbergichthys nudifrons (n = 7), Trematomus bernacchii (n = 1), T. newnesi (n = 1) and Harpagifer antarcticus (n = 2). Three species of Echinorhynchida: Aspersentis megarhynchus, Metacanthocephalus dalmori and M. johnstoni and four species of Polymorphida: Corynosoma arctocephali, C. bullosum, C. hamanni and C. pseudohamanni, were found. Prevalence of N. rossii and L. nudifrons was 100%. The mean abundance of infection of N. rossii (125.09) was larger than that of Notothenia coriiceps (82.93). Data of infection of N. rossii in 2007 was almost identical with that in 1979 (mean abundance 118.66). The most abundant in this host were A. megarhynchus, M. johnstoni, C. hamanni and C. pseudohamanni (mean abundances 36.36, 29.77, 13.86 and 44.73, respectively). In total Echinorhynchida were more abundant than Polymorphida in 2007/08 (66.18 versus 58.91). Reverse situation was in 1979 (mean abundance 47.36 for Echinorhynchida and 71.3 for Polymorphida. Only 7 L. nudifrons were examined in 2007/08 and Echinorhynchida were more numerous in this host (mean abundance 26.71) than Polymorphida (10.29). Single specimens of other fish were infected with a few Acanthocephala belonging to species recorded in the same hosts with those found in 1978/79.
Background. The hitherto published records of the parasite fauna of Baltic cod, Gadus morhua callarias cover commercially-caught adult fish. The aim of this study was to determine the composition of the parasite fauna of young Baltic cod, the relevant infection parameters and to relate those data to published records on the diet of cod. Materials and Methods. This survey was carried out on 154 young cod, caught in May and June 2002 in the Gulf of Puck, the Baltic Sea, Poland. The fish were examined using standard methods applied in parasitology. Results. No external parasites were found. In the digestive tracts of 58 cod, 3 species of parasites belonging to 2 higher taxa (Nematoda and Acanthocephala) were found. The dominant parasite was Echinorhynchus gadi Zoega in Müller, 1776. The mean abundance ranged from 0.15 to 2.75. The prevalence ranged from 14.6%, in the smallest fish, to 66.7% in the larger ones. Only two acanthocephalan specimens of Pomphorhynchus laevis (Zoega in Müller, 1776) and five nematode larvae of Hysterothylacium aduncum (Rudolphi, 1802) were found. Conclusion. The parasite fauna of young Baltic cod is significantly sparser than in larger fish examined by other authors. It is suggested that the occurrence of the species found, can be related to the composition of diet available.
During June and July of 2007, a total of 130 specimens of the fish Rastrelliger kanagurta Cuvier (Teleostei, Scombridae), ranging between 19–31 cm in total length, were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt, and examined for infections by acanthocephalans (65 fish/month). Of this number, 29 (22.30%) were slightly or heavily parasitized by the acanthocephalan Diplosentis nudus (Harada, 1938) Pichelin et Cribb, 2001 (Cavisomidae); no other helminth parasites were found in the intestine of R. kanagurta. Twenty-nine infrapopulations of D. nudus, ranging from 23–218 individuals were collected from the infected fishes. These infrapopulations were distributed in a well-defined fundamental niche along the intestine of R. kanagurta, where the distribution of male worms was not random with respect to female worms size and position and suggests that the male-male competition for access to female may be intense and may select for large males. No correlation between fish size and infrapopulation size was observed. Correlations between female-to-male sex ratio and infrapopulation size, numbers of females and their mean lengths, numbers of males and their mean lengths, mean female length and mean male length within infrapopulation were very strong, and clearly suggest that as the infrapopulation size increased, the number of females and their mean lengths decreased and the number of males and their mean lengths increased. Combination of these results strongly suggests density-dependent effects and competition between male worms. The relationship between the mean female length or size and the number of eggs within its pseudocoel was strongly positive; egg production by female worm significantly decreases as the infrapopulation size increases, suggesting density-dependent reduction in female worm fecundity. Tendency for the variability in male testes size was not significant in infrapopulations of D. nudus. All of these results are discussed.
The present study is the first record of acanthocephalan parasites in fish of the genus Hippocampus and of the order Syngnathiformes. It also provides the first reference to Corynosoma australe in fish from San Matías Gulf, Argentina. Parasites analyzed in the present study were morphologically similar to previous records in other marine fishes from Argentine Sea, however, they were comparatively more irregular in their dimensions with respect to previous records. Taking account information about seasonal presence, prevalence and mean intensity observed for C. australe in this study, it could be claimed that Patagonian seahorse plays an accidental role as paratenic host to this helminth. Potential paths of infection and dispersion of this parasite in the ecosystem of San Antonio Bay are discussed regarding the trophic relationships among crustaceans, fishes and marine mammals.
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