Cristin-resultat-ID: 341809
Sist endret: 18. januar 2010, 11:20
Resultat
Vitenskapelig artikkel
2007

Myxosporeans infecting Atlantic cod (Gadus morhua) in Norway: pests in cod culture?

Bidragsytere:
  • Egil Karlsbakk
  • Trond Einar Isaksen
  • D. Perez-Lopez
  • Karl Fredrik Ottem
  • Heidrun Plarre
  • Marianne Køie
  • mfl.

Tidsskrift

Parassitologia
ISSN 0048-2951

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2007
Volum: 49

Beskrivelse Beskrivelse

Tittel

Myxosporeans infecting Atlantic cod (Gadus morhua) in Norway: pests in cod culture?

Sammendrag

Cod culture is a modest but fast growing industry in Norway, and is already plagued by viral, bacterial and parasitic diseases. During a project establishing base-level prevalences of important viral and bacterial disease agents in wild cod stocks, we also examined some of the fish for myxosporeans. Adult cod was collected along the coast of W and N Norway. In addition, broodstock and juveniles from several cod farms were examined for myxosporean infections. Bile and urine were examined at 400-1000x magnification, while the eye-balls (i.e. sclera) was systematically examined for Myxobolus aeglefini infection. A total of 210 fish were examined, representing both local and migratory stocks, and 6 species of myxosporeans were discerned. Myxobolus aeglefini infected the cartilage of the eyes and cranium of 6% of the fish. In the gall bladder, spores of two species were encountered, Myxidium oviforme Parisi, 1912 sensu Auerbach (1912) part (ex cod) and Myxidium bergense Auerbach, 1910, infecting the liver bile ducts and the gall bladder, respectively. The overall prevalence of M. oviforme was 53%, but was higher in local stocks (56-76%) than in migratory fish (31%, Borgundfjorden, northern W Norway, N=52). Myxidium bergense was absent in local cod from southern Norway, but occurred in local fish from northern Norway and in migratory fish caught in Borgundfjorden (37%). A novel parvicapsulid-type infected the kidney, ureters and urinary bladder, found in the urine of 69% of the fish, but with a higher prevalence in migratory (88%) than local stocks (35-77%). However, in this case season was likely important, lowest prevalence occurred in fish caught during summer (35% July), while high prevalences occurred in winter (69-88%). Zschokkella hildae Auerbach, 1910 infections are common throughout Norway (44% with spores) but always occurred in low intensities. Of the migratory cod, 53% were infected. Zschokkella sp. was only detected in a few cod of Barents Sea origin. Myxidium oviforme infections were observed in wild-caught broodstock cod kept for up to 4 years in tanks on land, with water treatment that should exclude myxosporean re-infections. Hence these infections must be long-lasting, likely due to an observed budding of plasmodia in the liver. Zschokkella hildae was the most common myxosporean in cage reared cod, while infections in the biliary system were absent. Parvicapsulidae gen. sp. infects juvenile cod reared in shallow closed bays, and hence likely has a life cycle involving annelid hosts living in shallow waters. Among Myxozoa, so far only Myxobolus aeglefini have been observed to cause significant pathology in Norwegian farmed cod.

Bidragsytere

Egil Erlingsson Karlsbakk

Bidragsyterens navn vises på dette resultatet som Egil Karlsbakk
  • Tilknyttet:
    Forfatter
    ved Havforskningsinstituttet
Aktiv cristin-person

Trond Einar Isaksen

  • Tilknyttet:
    Forfatter
    ved Institutt for biovitenskap ved Universitetet i Bergen

D. Perez-Lopez

  • Tilknyttet:
    Forfatter

Karl Fredrik Ottem

  • Tilknyttet:
    Forfatter
    ved NORCE Klima og miljø ved NORCE Norwegian Research Centre AS

Heidrun Nylund

Bidragsyterens navn vises på dette resultatet som Heidrun Plarre
  • Tilknyttet:
    Forfatter
    ved Institutt for biovitenskap ved Universitetet i Bergen
1 - 5 av 7 | Neste | Siste »