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

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.

Download Full-text

Lungworm (Nematoda: Metastrongyloidea) infections in Canadian phocids

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f97-306 ◽

1998 ◽

Vol 55 (4) ◽

pp. 825-834 ◽

Cited By ~ 9

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.

Download Full-text

Serologic Evidence of Brucella Spp. Exposure in Atlantic Walruses (Odobenus Rosmarus Rosmarus) and Ringed Seals (Phoca Hispida) of Arctic Canada

ARCTIC ◽

10.14430/arctic1214 ◽

1996 ◽

Vol 49 (4) ◽

Cited By ~ 20

Author(s):

Ole Nielsen ◽

Klaus Nielsen ◽

Robert E.A. Stewart

Keyword(s):

Phoca Hispida ◽

Arctic Canada ◽

Ringed Seals ◽

Odobenus Rosmarus ◽

Serologic Evidence ◽

Odobenus Rosmarus Rosmarus

Download Full-text

Experimental transmission of Otostrongylus circumlitus (Railliet, 1899) (Metastrongyloidea: Crenosomatidae), a lungworm of seals in eastern arctic Canada

Canadian Journal of Zoology ◽

10.1139/z97-762 ◽

1997 ◽

Vol 75 (9) ◽

pp. 1364-1371 ◽

Cited By ~ 16

Author(s):

Emmanuelle Bergeron ◽

Jean Huot ◽

Lena N. Measures

Keyword(s):

Marine Mammals ◽

Pelagic Fish ◽

Intermediate Hosts ◽

Phoca Hispida ◽

Experimental Transmission ◽

Larval Stages ◽

Third Stage ◽

Young Of The Year ◽

Otostrongylus Circumlitus ◽

Hippoglossoides Platessoides

The transmission of few metastrongyloids infesting marine mammals is known. The results of experimental infections using Otostrongylus circumlitus (Crenosomatidae), a lungworm of pinnipeds, suggested that this metastrongyloid uses fish as intermediate hosts. Various marine organisms (crustaceans, molluscs, and fish) were exposed to first-stage larvae from naturally infected young-of-the-year ringed seals (Phoca hispida) from northern Quebec (Salluit). The first and second moults occurred 3 and 56 days post exposure in the mucosa and muscularis of the intestine of American plaice (Hippoglossoides platessoides) kept at 4 °C. Third-stage larvae were found under the intestinal serosa. Attempts to infect invertebrates were unsuccessful. Transmission to seals may occur from mid-June through the autumn as young seals start feeding intensively on invertebrates and fish. First-stage larvae leave the lungs via the bronchial escalator and are swallowed and released into the sea with the faeces of seals, where they would be available to benthic or pelagic fish. The morphology of the first three larval stages is described.

Download Full-text

Haul-out behaviour and densities of ringed seals (Phoca hispida) in the Barrow Strait area, N.W.T.

Canadian Journal of Zoology ◽

10.1139/z79-263 ◽

1979 ◽

Vol 57 (10) ◽

pp. 1985-1997 ◽

Cited By ~ 35

Author(s):

Kerwin J. Finley

Keyword(s):

Wind Speed ◽

Early Morning ◽

Maximum Density ◽

Stable Population ◽

The Sun ◽

High Wind ◽

Phoca Hispida ◽

High Wind Speed ◽

Ringed Seals ◽

Calm Weather

Numbers of ringed seals hauled out on the ice began to increase in early June. Numbers on the ice were highest from 0900 to 1500 hours Central Standard Time and lowest (average 40–50% of peak) in early morning. Seals commonly remained on the ice for several hours, and occasionally (during calm weather) for > 48 h. Numbers on the ice were reduced on windy days and possibly also on unusually warm, bright and calm days. Seals tended to face away from the wind (particularly with high wind speed) and oriented broadside to the sun. Seals usually occurred singly (60–70% of all groups) at their holes.Numbers of seals hauled out at Freemans Cove remained relatively constant during June (maximum density 4.86/km2), whereas at Aston Bay numbers increased dramatically to a maximum density of 10.44/km2 in late June. The increase was thought to be due to an influx of seals abandoning unstable ice. The density of seal holes at Freemans Cove (5.92/km2) was much higher than at Aston Bay (2.73/km2). The ratio of holes to the maximum numbers of seals (1.12:1) at Freemans Cove represents a first estimate of this relationship in an apparently stable population.

Download Full-text

Distribution and abundance of ringed (Phoca hispida) and bearded seals (Erignathus barbatus) in western Hudson Bay

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f96-346 ◽

1997 ◽

Vol 54 (4) ◽

pp. 914-921 ◽

Cited By ~ 12

Author(s):

N J Lunn ◽

I Stirling ◽

S N Nowicki

Keyword(s):

Polar Bear ◽

Hudson Bay ◽

Phoca Hispida ◽

Current Estimate ◽

Ringed Seals ◽

Erignathus Barbatus ◽

The Mean ◽

Western Hudson Bay ◽

The Relationship ◽

Bearded Seals

We flew a medium-altitude, systematic, strip-transect survey for ringed (Phoca hispida) and bearded seals (Erignathus barbatus) over western Hudson Bay in early June 1994 and 1995. The mean density (per square kilometre) of ringed seals hauled out on the ice was four times higher in 1995 (1.690) than in 1994 (0.380). The 1994 survey appeared to underestimate seal abundance because it was flown too late. Ringed seals preferred high ice cover habitat (6 + /8 ice) and, within this habitat, favoured cracking ice and large floes. We found no consistent effect of either wind or cloud cover on habitat preference. We estimated a total of 1980 bearded seals and 140<|>880 ringed seals hauled out on the sea ice in June 1995. A recent review of the relationship between ringed seal and polar bear (Ursus maritimus) populations suggests that a visible population of this size should support a population of up to 1300 polar bears, which is in general agreement with the current estimate of 1250-1300 bears in western Hudson Bay.

Download Full-text

The scent of rutting male ringed seals(Phoca hispida)

Journal of Zoology ◽

10.1111/j.1469-7998.1992.tb07509.x ◽

1992 ◽

Vol 226 (4) ◽

pp. 681-689 ◽

Cited By ~ 19

Author(s):

M. Ryg ◽

Y. Solberg ◽

C. Lydersen ◽

T. G. Smith

Keyword(s):

Phoca Hispida ◽

Ringed Seals

Download Full-text

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

Canadian Journal of Zoology ◽

10.1139/z87-162 ◽

1987 ◽

Vol 65 (4) ◽

pp. 1021-1027 ◽

Cited By ~ 38

Author(s):

Christian Lydersen ◽

Ian Gjertz

Keyword(s):

Sex Ratio ◽

Ringed Seal ◽

Adult Males ◽

Population Parameters ◽

Phoca Hispida ◽

Age Class ◽

Ringed Seals ◽

Males And Females ◽

The Mean ◽

Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

Download Full-text