Lungworm (Nematoda: Metastrongyloidea) infections in Canadian phocids

1998 ◽  
Vol 55 (4) ◽  
pp. 825-834 ◽  
Author(s):  
Jean-François Gosselin ◽  
Lena N Measures ◽  
Jean Huot
Keyword(s):  
Detrimental Effect ◽  
Halichoerus Grypus ◽  
Bearded Seal ◽  
Eastern Canada ◽  
New Host ◽  
Ringed Seals ◽  
Phoca Groenlandica ◽  
Harbour Seals ◽  
Young Of The Year ◽  
Otostrongylus Circumlitus

Otostrongylus circumlitus (Railliet, 1899) was found in 5% (16/308) of grey seals (Halichoerus grypus), 6% (1/17; intensity = 38) of harbour seals (Phoca vitulina), and none of 100 harp seals (Phoca groenlandica) from eastern Canada and none of 31 ringed seals (Phoca hispida) from Holman, Northwest Territories. Eighty-two percent of these infections were observed in young-of-the-year seals. Filaroides (Parafilaroides) gymnurus (Railliet, 1899), detected in nodules in the superficial parenchyma of the lungs, infected 24% (5/16) of grey seals, 27% (4/15) of harbour seals, 57% (29/51) of harp seals, 81% (25/31) of ringed seals, and one stranded bearded seal (Erignathus barbatus) (new host report for harp, ringed, and bearded seals; new locality report for Holman). Filaroides (Parafilaroides) hispidus Kennedy, 1986 was found in systematically sliced lungs of grey seals (2/3; new host report) and ringed seals (2/7) but not in harp seals (n = 11) or harbour seals (n = 5). Intensity ranged from 37 to 3570 for F. (P.) gymnurus and from 295 to 1196 for F. (P.) hispidus. No detrimental effect on body condition of seals could be associated with infection by lungworms.

Redescription of Filaroides (Parafilaroides) gymnurus (Railliet, 1899) (Nematoda: Metastrongyloidea), with comments on other species in pinnipeds

1997 ◽  
Vol 75 (3) ◽  
pp. 359-370 ◽  
Author(s):  
Jean-François Gosselin ◽  
Lena N. Measures
Keyword(s):  
Phoca Vitulina ◽  
Valid Species ◽  
Halichoerus Grypus ◽  
Museum Specimens ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Phoca Groenlandica ◽  
Harbour Seals ◽  
Species Inquirenda

The species Filaroides (Parafilaroides) gymnurus (Railliet, 1899) Anderson, 1978 is redescribed, based on examination of mature fifth-stage specimens from wild infected ringed seals (Phoca hispida), harp seals (Phoca groenlandica), harbour seals (Phoca vitulina), and grey seals (Halichoerus grypus) collected in eastern and arctic Canadian waters. Mature specimens of Filaroides (Parafilaroides) hispidus Kennedy, 1986 from ringed seals and grey seals were also examined. Comparison of these worms with museum specimens and the literature led to a review of species in the subgenus Parafilaroides (Dougherty, 1946) Anderson, 1978. Filaroides (Parafilaroides) gymnurus (Railliet, 1899) Anderson, 1978, F. (P.) decorus (Dougherty and Herman, 1947) Anderson, 1978, F. (P.) hydrurgae (Mawson, 1953) Kennedy, 1986, and F. (P.) hispidus Kennedy, 1986 are recognized as valid species. Filaroides (Parafilaroides) arcticus (Delyamure and Alekseev, 1966) Kennedy, 1986 and F. (P.) krascheninnikovi (Yurakhno and Skrjabin, 1971) Kennedy, 1986 are synonymized with F. (P.) gymnurus (Railliet, 1899) Anderson, 1978. Filaroides (Parafilaroides) caspicus (Kurochkin and Zablotsky, 1958) Kennedy, 1986 is considered a species inquirenda.

Predation by Sharks on the Grey Seal (Halichoerus grypus) in Eastern Canada

1983 ◽  
Vol 40 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Paul Brodie ◽  
Brian Beck
Keyword(s):  
Key Words ◽  
Population Size ◽  
Halichoerus Grypus ◽  
Longline Fishery ◽  
Grey Seal ◽  
Eastern Canada ◽  
The Past ◽  
Harbour Seals ◽  
Commercially Important ◽  
Important Fish

The increase in population size of the grey seal (Halichoerus grypus) off eastern Canada over the past 20 yr may be attributed to a decrease in shark stocks, their supposed predators. Reduction of the shark population is presumed to have resulted from a directed longline fishery and, of greater significance, from a change in the fishery for swordfish (Xiphias gladius) from selective harpooning to pelagic longlining, which has produced a large bycatch of sharks. The resulting enhanced survival of grey seals is reflected in greater infestation of commercially important fish species by the codworm (Phocanema decipiens).Key words: grey seals, harbour seals, sharks, swordfish, codworm, predation, fisheries

Mercury in Seals from Eastern Canada

1973 ◽  
Vol 30 (6) ◽  
pp. 843-846 ◽  
Author(s):  
D. E. Sergeant ◽  
F. A. J. Armstrong
Keyword(s):  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Eastern Canada ◽  
Small Pelagic Fish ◽  
Marine Food Web ◽  
Cystophora Cristata ◽  
Pagophilus Groenlandicus ◽  
Harbour Seals ◽  
Order Of Magnitude ◽  
Marine Food

Mercury concentrations in the tissues of four species of seals from individual localities in eastern Canada were highest in liver (usually 1–100 ppm) but up to 387 ppm and lowest in blubber (usually 0.1 ppm). Levels in muscle ranged from < 0.16 to 2.35 ppm. Values similar to those in muscle were found in the few specimens of heart, intestine, and lungs analyzed, and higher values in kidney and hair. Ratios of mercury in the liver to that in the muscle for adult seals were much greater than those found in two species of freshwater fish and three species of domestic animals exposed to wide ranges of mercury concentrations in their food. The ratios for seal pups, however, resembled those in the other animals.Mercury in seals increased with age and appeared to vary with the position in the marine food web of the organisms which they eat. Harp seals (Pagophilus groenlandicus), which feed on small pelagic fish and crustaceans, accumulated an order of magnitude less mercury than grey (Halichoerus grypus) and harbour (Phoca vitulina) seals, which live on large pelagic and benthic fish and cephalopods. However, grey and harbour seals are resident in eastern Canadian waters, which presumably contain higher mercury levels than arctic waters, where harp seals spend about half the year. Yet hood seals (Cystophora cristata), which spent more than half the year in arctic waters but feed on large fish and cephalopods, had mercury levels as high as grey and harbour seals.

Susceptibility of Grey (Halichoerus grypus) and Harp (Phoca groenlandica) Seals to the Influenza Virus and Mycoplasma of Epizootic Pneumonia of Harbor Seals (Phoca vitulina)

1984 ◽  
Vol 41 (1) ◽  
pp. 151-156 ◽  
Author(s):  
J. R. Geraci ◽  
D. j. St. Aubin ◽  
I. K. Barker ◽  
V. S. Hinshaw ◽  
R. G. Webster ◽  
...  
Keyword(s):  
Influenza Virus ◽  
New England ◽  
Influenza A ◽  
Phoca Vitulina ◽  
Lung Homogenate ◽  
Halichoerus Grypus ◽  
Harbor Seals ◽  
Eastern Canada ◽  
Cystophora Cristata ◽  
Phoca Groenlandica

Six grey, Halichoerus grypus, and 12 harp, Phoca groenlandica, seals were inoculated intratracheally with lung homogenate containing influenza virus A/seal/Mass/1/80 and mycoplasma from harbor seals, Phoca vitulina, which had died in an epizootic of pneumonia. The grey seals were refractory to infection, whereas some of the harp seals developed mild pneumonia. Virus was recovered from 4 of 10 harp seals necropsied, and antibodies were produced in 2 survivors. The mycoplasma given alone to 2 grey seals did not replicate or produce infection and was recovered from only 1 of 12 harp seals inoculated. We examined 99 grey, 102 harp, 14 harbor, and 7 hooded seals (Cystophora cristata) from eastern Canada and found antibodies to avian influenza A/seal/Mass/1/80 in 3 adult male grey seals from Sable Island, N.S.; this virus is apparently adaptable to other seal species. Related forms of the virus are highly suspect as the cause of past epizootics, and one is currently responsible for a new outbreak of pneumonia in New England harbor seals.

Lungworm (Otostrongylus circumlitus) infections in ringed seals (Phoca hispida) from eastern Arctic Canada

1997 ◽  
Vol 54 (10) ◽  
pp. 2443-2448 ◽  
Author(s):  
E Bergeron ◽  
L N Measures ◽  
J Huot
Keyword(s):  
Protective Immunity ◽  
Subsequent Development ◽  
Condition Index ◽  
Diving Behavior ◽  
Phoca Hispida ◽  
Arctic Canada ◽  
Ringed Seals ◽  
Severe Infections ◽  
Young Of The Year ◽  
Otostrongylus Circumlitus

Otostrongylus circumlitus, a metastrongyloid nematode found in the lungs of ringed seals (Phoca hispida) and other pinnipeds, may affect the health of seals and reduce diving capacity. Of five sites sampled in eastern Arctic Canada (190 seals examined), Salluit, Que., is an important enzootic zone (prevalence 48.2%, n = 27). Maximum intensity of O. circumlitus was 32 worms. Infection is restricted to young-of-the-year seals and may have an impact on recruitment of the population. Local geographic conditions may influence transmission of the parasite and thus prevalence and intensity of O. circumlitus among populations of ringed seals. No condition index used showed any significant relationship to infection, but prevalence and intensity were related to sternal blubber thickness (0.01 < p < 0.05) indicating that this parasite may have an effect on the physical condition of seals. Otostrongylus circumlitus may have an indirect effect on seals by modifying their diving behavior. Severe infections may lead to death, but light infections could be lost after a certain time with subsequent development of protective immunity.

scholarly journals Anophryocephalus inuitorum sp.nov. and A. arcticensis sp.nov. (Eucestoda: Tetrabothriidae) in ringed seals (Phoca hispida hispida) and harp seals (Phoca groenlandica) from high-latitude seas of eastern Canada and the Arctic basin

1995 ◽  
Vol 73 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Eric P. Hoberg ◽  
Lena N. Measures
Keyword(s):  
High Latitude ◽  
Genital Atrium ◽  
Canadian Arctic ◽  
Arctic Basin ◽  
The Arctic ◽  
Phoca Hispida ◽  
Eastern Canada ◽  
Ringed Seals ◽  
Phoca Groenlandica ◽  
Eastern Canadian Arctic

Anophryocephalus inuitorum sp.nov. and A. arcticensis sp.nov. are described from ringed seals (Phoca hispida hispida) in the eastern Canadian Arctic; the latter species is also reported from harp seals (Phoca groenlandica) in the Gulf of St. Lawrence. Anophryocephalus inuitorum is most similar to A. skrjabini, but can be distinguished by fewer testes (14–27) and smaller dimensions of the strobila, neck (3.0–5.9 mm long), and cirrus sac (31–70 μm long), diameter of the genital atrium (44–68 μm), and length of the male canal (23–42 μm long). Anophryocephalus arcticensis resembles A. nunivakensis in the structure of the scolex, but is readily distinguished by a longer neck (8.9–14.7 mm), an elongate cirrus sac (60–98 × 44–73 μm) with a substantially thicker muscular wall, a more globular vitelline gland, and larger embryophores (29–41 μm long) and oncospheres (24–34 μm long). These are the first species of Anophryocephalus to be described from phocines in the eastern Canadian Arctic, and are included in a revised key for the genus.

Fatal Interspecies Mating Attempts of a Grey Seal (Halichoerus grypus) with Harbour Seals (Phoca vitulina) on the German North Sea Coast

2020 ◽  
Vol 174 ◽  
pp. 166
Author(s):  
K. Hülskötter ◽  
S. Rohner ◽  
S. Groß ◽  
J. Lakemeyer ◽  
M. Fähndrich ◽  
...  
Keyword(s):  
North Sea ◽  
Phoca Vitulina ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Harbour Seals ◽  
Sea Coast ◽  
North Sea Coast
Sign in / Sign up

Export Citation Format

Share Document