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

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.

1998 ◽  
Vol 55 (4) ◽  
pp. 825-834 ◽  
Author(s):  
Jean-François Gosselin ◽  
Lena N Measures ◽  
Jean Huot

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.


1990 ◽  
Vol 47 (6) ◽  
pp. 1223-1227 ◽  
Author(s):  
Morten Ryg ◽  
Christian Lydersen ◽  
Nina H. Markussen ◽  
Thomas G. Smith ◽  
Nils Are Øritsland

We have investigated the relationships between percent blubber content and xiphostemal blubber thickness or girth-to-length ratios in ringed seal (Phoca hispida), harp seal (Phoca groeniandica), and grey seal (Halichoerus grypus). The blubber content was significantly correlated with blubber depths and girth-to-length ratios in all three species, in addition, we have developed an estimator for percent blubber content (the LMD-index) based on standard length (L, in meters), body mass (M, in kilograms), and on blubber thickness (d, in meters) measured at a defined position dorsally. From these variables the percent blubber content (B%) can be estimated by the expression B% = 4.44 + 5693 [Formula: see text], with a standard error of the estimate of three percentage units. This index also gave reasonable estimates for blubber content in three harbour seals (Phoca vitulina) and eight bearded seals (Erignatus harbatus).


2020 ◽  
Vol 174 ◽  
pp. 166
Author(s):  
K. Hülskötter ◽  
S. Rohner ◽  
S. Groß ◽  
J. Lakemeyer ◽  
M. Fähndrich ◽  
...  

2015 ◽  
Vol 13 ◽  
pp. 41-43
Author(s):  
Erlingur Hauksson

Grey seals (Halichoerus grypus Fabricius) and harbour seals (Phoca vitulina L.) have been surveyed on the coasts of Iceland since 1980. During the period 1980-2012, both seal species have declined markedly in numbers at the Icelandic coast. The grey seal has established a considerable breeding site on the northern spit of the Surtsey island. This is at present one of the biggest grey seal rookeries on the southern shores of Iceland, with estimated about 60 pups born there in the autumn of 2012. On the other hand, the harbour seal has not been numerous on Surtsey during breeding time in the summer. Breeding sites of harbour seals on the south coast of Iceland closest to Surtsey are in the estuaries of the glacial rivers Ölfusá, Þjórsá, Markarfljót and Kúðafljót. Harbour seals, however, haul-out in great numbers on the northern shores of Surtsey during the winter, presumably using the island as a resting place after foraging in the adjacent waters.


1977 ◽  
Vol 55 (12) ◽  
pp. 1936-1941 ◽  
Author(s):  
D. St. Aubin ◽  
J. R. Geraci

The distributions of alanine aminotransferase (AIAT), aspartate aminotransferase (AspAT), ornithine carbamyl transferase (OCT), and sorbitol dehydrogenase (SDH) were determined in the tissues of ringed seals, Phoca hispida, harp seals, P. groenlandica, and grey seals, Halichoerus grypus. In all species, AIAT, OCT, and SDH were concentrated primarily in the liver, while AspAT had a more widespread distribution. Species differences were noted in the distribution of AspAT. In grey and harp seals cardiac muscle generally contained the greatest concentration of activity while in ringed seals the highest activity was found in the liver. Reference plasma values were determined in six clinically normal captive ringed seals.


2002 ◽  
Vol 119 (3) ◽  
pp. 399-412 ◽  
Author(s):  
Madeleine Nyman ◽  
Jaana Koistinen ◽  
Marie Louise Fant ◽  
Terttu Vartiainen ◽  
Eero Helle

2002 ◽  
Vol 80 (3) ◽  
pp. 442-449 ◽  
Author(s):  
Wayne T Stobo ◽  
L Paul Fanning ◽  
Brian Beck ◽  
G Mark Fowler

Three species of anisakine nematodes (Pseudoterranova decipiens, Contracaecum osculatum, Anisakis simplex) co-occur in the stomachs of Sable Island harbour seals (Phoca vitulina). The sealworm, P. decipiens, was the commonest nematode in these seals. Anisakis simplex was found in much smaller numbers, none mature, indicating that the harbour seal is not a true final host to this parasite. Contracaecum osculatum was rare but half were mature. Pseudoterranova decipiens increased in abundance with size of the seal. An inverse relationship was observed between P. decipiens abundance and the age of seals of similar size, probably owing to changes in diet. Numbers of P. decipiens may have declined over the summer, coincident with an increase in the proportion of mature worms in the stomach. From similarities between the worm infections of grey seals (Halichoerus grypus) and harbour seals, we infer that A. simplex abundance may also exhibit a decline in abundance. Contracaecum osculatum was only encountered during the latter half of the year, suggesting an association with prey species of corresponding periodicity in their distribution. We estimate that the abundance of sealworm in harbour seals is about 2.5% of that carried by the grey seal population. This could imply that harbour seals represent an insignificant vector of the sealworm infecting commercial fish species in the Northwest Atlantic, provided density-dependent relationships exist between worm abundances in different host species.


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