Anisakidae in beluga whales Delphinapterus leucas from Hudson Bay and Hudson Strait.

A total of 190 nematodes was isolated from the stomachs of 13 beluga whales Delphinapterus leucas from the Arctic part of Hudson Bay and Hudson Strait. Infection intensity ranged from 1 to 57 specimens and prevalence was 84.62%. Morphological examination of the nematodes revealed the presence of 3 species: Pseudoterranova decipiens sensu lato, Contracaecum osculatum s.l., and Anisakis simplex s.l. Molecular analysis by PCR-based restriction fragment length polymorphism (PCR-RFLP) resulted in the identification of 4 species: Pseudoterranova bulbosa, Contracaecum osculatum A and C, and Anisakis simplex sensu stricto. The nematodes were present in 3 developmental stages: L3 (159 specimens), L4 (16 larvae), and adults (15 worms: 11 males and 4 females).

Anisakid nematodes in dolphins (Cetacea: Delphinidae) from the Baltic Sea area.

Dolphins are rarely observed in the Baltic Sea, making only sporadic appearances as a result of their migrations. The study included six specimens: four white-beaked dolphins Lagenorhynchus albirostris and two striped dolphins Stenella coeruleoalba. Their gastrointestinal tracts were found to contain the nematodes Anisakis simplex (in both species) and Contracaecum sp. (only in the white-beaked dolphins). This is the first record of Anisakidae nematodes in dolphins found in the Baltic Sea.

A global checklist of the parasites of the harbor porpoise Phocoena phocoena, a critically-endangered species, including new findings from the Baltic Sea.

The common harbor porpoise is a widely-distributed marine mammal with three known subspecies, including P. phocoena phocoena, with a clearly distinct and critically endangered (CR) subpopulation from the Baltic Sea (Baltic Proper). As part of an assessment of the condition and health threats of these mammals, it is important to conduct parasitological monitoring. The aim of the study was therefore to compare the data on porpoise parasitofauna from this subpopulation with those on porpoises from other areas. The study included 37 individuals from 1995 to 2019; eight species of parasites were found (prevalence 83.8%, mean intensity 724.2, range 2-3940), with a predominance of lung nematodes - Stenurus minor (94.7%), Torynurus convolutus (69.4%), Pseudalius inflexus (63.8%), Halocercus invaginatus (22.2%); the highest intensity was recorded for S. minor (989, 53-2928). Two species of Anisakidae (Anisakis simplex - 33.3%, Contracaecum sp. - 20.0%) were found in the digestive tracts, which were a new record for this population. The fluke Campula oblonga was found in the livers of 31.3% of porpoises. The tapeworm Diphylobothrium stemmacephalum was also recorded in the intestine of one individual; this is typical for these hosts, but previously undetected in the Baltic subpopulation. Parasites coexisted in numerous hosts, constituting a heavy burden for them. The obtained data were compared with those from the P. phocoena parasitofauna from other regions, based on a compiled checklist (1809-2021) including all species of porpoise parasites (55 taxa). Compared to the worldwide porpoise parasitofauna checklist, the number of parasites found in the nominative subspecies (Baltic Proper subpopulation) is small: including only 10 taxa (eight in the current study). These species are typical of porpoises and usually the most common; however, the level of infection of Baltic porpoises (intensity and total parasite load) is very high, which can undoubtedly have a negative impact on their condition and overall health.

The helminthofauna of the garfish Belone belone (Linnaeus, 1760) from the southern Baltic Sea, including new data.

The garfish Belone belone (Linnaeus, 1760) is a marine fish which can be found in the shallow waters of the Baltic Sea in the spring and summer spawning period. In 2010 and in 2016, 73 specimens of garfish collected in the Gulf of Gdansk (southern Baltic Sea) were examined for the presence of helminths. The fish were found to support the nematode Anisakis simplex (Rudolphi, 1809) L3, Hysterothylacium aduncum (Rudolphi, 1802) L4, ad., Contracaecum sp. L3 as well as the acanthocephalan Echinorhynchus gadi Zoega in Müller, 1776. For all garfish caught in 2010 and 2016, the overall prevalence of infection by all parasites was 38.4%, with a mean intensity of 2.9 (range 1-5). The dominant parasites were H. aduncum (20.5%, 1.8) and E. gadi (17.8%, 2.1). This study constitutes the first record of Contracaecum larvae in garfish in the Polish exclusive economic zone of the Baltic Sea.

Checklist of the parasites of European eel Anguilla anguilla (Linnaeus, 1758) (Anguillidae) in Poland.

The present paper lists all parasite species of the European eel Anguilla anguilla (Linnaeus, 1758), recorded in Poland, in both its saltwater and freshwater habitats. The list has been drawn up, based on data acquired since 1844. The majority of included parasite species are presented with fish infection parameters together with data on their developmental stages and occupied microhabitats, localities and dates of collection of the eels themselves. The database includes 62 parasite taxa (including 50 species, nine identified to the genus level and three to higher taxa), representing at least 47 genera and 39 families. The most frequently-noted parasites of the European eel are the cestode Bothriocephalus claviceps, the nematodes Anguillicoloides crassus, Camallanus lacustris and Raphidascaris acus and the acanthocephalan Acanthocephalus lucii. Four alien species have been noted from this host: A. crassus, the monogeneans Pseudodactylogyrus anguillae and Pseudodactylogyrus bini and the acanthocephalan Paratenuisentis ambiguus. The present list includes both new host records and earlier records not included in previous lists of parasites of eels.

[Contamination of playgrounds in Gdansk city with parasite eggs]. / Skazenie placów zabaw Gdanska jajami pasozytów.

INTRODUCTION: Nematodes of Toxocara genus are common parasites of dogs and cats. These animals are the main source of dangerous zoonoses. The main source of toxocarosis among children are sandpits which are contaminated with dog and cat faeces. We examined the contamination of playgrounds with parasite eggs in Gdatisk city, and frequency of infections of dogs and cats in the area under study. MATERIAL AND METHODS: Samples of sand were taken from a surface of sandpits (to depth about 3 cm). All samples were collected in amount of 100 g. Samples of faeces were taken from various places of the playgrounds. Two methods were applied: flotation and decantation by Fülleborn-Willis in modification by W6jcik. RESULTS: Out of 162 sand samples examined 21 (13%) were positive. Out of 54 faeces samples examined 23 (42.6%) were positive. We observed some differences in the degree of parasite species occurrence. The most dominated were Toxocara spp. (6.2% in sand samples and 11% in faeces samples) and Toxascaris leonina (11% in faeces). Eggs of Uncinaria stenocephala and Ancylostoma canimum, as well as proglotides of Dipylidium caninum were found sporadically.

Anisakids of seals found on the southern coast of Baltic Sea.

In the present study 5 grey seals (Halichoerus grypus), 3 common seals (Phoca vitulina) and 1 ringed seal (Pusa hispida) bycaught or stranded on the Polish Baltic Sea coast in years 2000-2006 were investigated for the infestation of parasitic anisakid nematodes. 749 of anisakids were found. The most common were: Contracaecum osculatum (59.3%) and Pseudoterranova decipiens (31.0%). There were also small numbers of Anisakis simplex (0.8%). After performing RFLP three sibling species were found. C. osculatum was identified as C. osculatum C, P decipiens was identified as P. decipiens sensu stricto and A. simplex - A. simplex sensu stricto. Nematodes found in seals were mostly in L4 and adult life stage - both of them were equal with some minor variations among the specimens. Sex ratio was also equal, but there was slight excess of males in some cases. There was a minority of L3 larvae belonging to A. simplex species (0.8%).

Anisakid nematodes of Greenland halibut Reinhardtius hippoglossoides from the Barents Sea.

Parasitic nematodes from the body cavity of 94 Greenland halibut (Reinhardtius hippoglossoides) caught in the Barents Sea were examined. Nematode species were identified using both morphological and molecular methods. Four morphospecies were found: Anisakis simplex s.l., Contracaecum osculatum s.l., Pseudoterranova decipiens s.l., and Hysterothylacium aduncum. The most prevalent were C. osculatum s.l. (89.4%) and A. simplex s.l. (86.2%). Mean intensities for these 2 species were 7.8 and 45.2, respectively. The number of parasites was directly proportional to the fish length. The following 6 parasite species, including 3 cryptic species of Contracaecum sp., were identified using molecular methods: A. simplex sensu stricto, C. osculatum A, C. osculatum B and C (the last 2 as host records for halibut), Pseudoterranova bulbosa, and H. aduncum. Mixed infections of C. osculatum A, B, and C were observed.

Mitochondrial DNA of Anisakis simplex s.s. as a potential tool for differentiating populations.

Anisakis simplex s.s. specimens from Gadus morhua, Gadus ogac, Reinhardtius hippoglossoides, Clupea harengus, Micromesistius poutassou, Pleurogrammus monopterygius, and Oncorhynchus nerka, caught in the north Atlantic and Pacific, were examined. Identity of the parasite species was confirmed using a molecular key. All specimens were used for amplifying a part of the non-coding sequence of the AT-rich region, flanked by the nad6-nad4L-trnW-trnE-rrnS-trnS2, and trnN-trnY-nad1 genes. This part of the mtDNA was chosen as a promising fragment, which could yield information regarding population differentiation. The number of samples and their geographical origin was sufficient to compare the 2 regions. The Bayesian analysis provided strong support for a population split into 2 groups, one representing A. simplex s.s. samples from the Pacific, and the other representing all the Atlantic samples. It is highly probable that observed subpopulations were constituted after the connection between the Atlantic and Pacific had been closed and movement between these 2 oceans was prevented.

Anisakid parasites of fishes caught on the African shelf.

Anisakids of Scomber japonicus, Trachyrincus scabrus, Sardina pilchardus, Merluccius polli, Trachurus trachurus, and Hoplostethus cadenati from African shelf are reported. Parasites were extensively studied with respect to their morphology and sequence analysis of the rDNA fragment (containing internal transcribed spacer [ITS]-1, 5.8S subunit and ITS-2); all of them are approximately 1,000 base pairs. Digestion of the amplified region and its sequencing revealed the presence of a sibling species (A. simplex s.s. and A. pegreffii). Still other sequences represented closely related, but not sibling, species, i.e., Anisakis brevispiculata, A. ziphidarum, and A. physeteris; there were also 2 undescribed anisakid species. These species were temporarily described as Anisakis sp. HC-2005 and Anisakis sp. MP-2005 (found, respectively, in Hoplostethus cadenati and Merluccius polli). The study shows that the parasitic fauna of fishes reflects not only the geographic range of anisakid nematodes but also the feeding behavior of the hosts serving as links in the parasites' life cycles.