Seatrout (Salmo trutta) is a natural host for Parvicapsula pseudobranchicola (Myxozoa, Myxosporea), an important pathogen of farmed Atlantic salmon (Salmo salar)

Particle and Fibre Toxicology

Egil Karlsbakk³  Turhan Markussen²  Trygve T Poppe¹  Haakon Hansen² 

[1] Norwegian University of Life Sciences, School of Veterinary Medicine, Ås, N-1432, Norway;Norwegian Veterinary Institute, P.O. Box 750 Sentrum, Oslo, N-0106, Norway;Institute of Marine Research, Nordnes Bergen, 5817, Norway

关键词: Norway;    Parvicapsulidae;    Marine Parasites;    Salmonids;    Life-cycle;    Natural host;   

Others  :  1172271
DOI  :  10.1186/s13071-015-0828-z

 received in 2015-02-06, accepted in 2015-03-25,  发布年份 2015

【 摘 要 】

Background

Parvicapsula pseudobranchicola (Myxozoa) causes widespread infections in farmed Atlantic salmon in northern Norway. Heavily infected salmon become runts, probably due to vision impairment or blindness. The salmon are likely infected by waterborne actinospores, released by an alternating annelid host, but the life cycle of P. pseudobranchicola is unknown. Seatrout and Arctic charr have been considered possible hosts for the parasite, but firm evidence has been lacking.

Findings

We show for the first time the presence of mature spores of P. pseudobranchicola in seatrout. The seatrout were infected with high intensities of P. pseudobranchicola in the pseudobranchs in early April. The presence of mature spores in early spring suggests that the fish had been infected late the previous year, a pattern of infection similar to that observed for farmed salmon stocked in autumn. Although heavily infected, the fish did not display any symptoms consistent with parvicapsulosis. The results suggest that the life cycle of P. pseudobranchicola is more adapted to seatrout, rather than to Atlantic salmon.

Conclusions

The presence of mature spores of P. pseudobranchicola in seatrout confirms that seatrout is a natural host for this myxosporean and this is also the first record of these spores in the pseudobranch of a wild salmonid. Furthermore, wild trout from non-farming areas may become heavily infected with P. pseudobranchicola, developing pseudobranch pathology resembling that of farmed Atlantic salmon suffering from parvicapsulosis.

【 授权许可】

   
2015 Hansen et al.; licensee BioMed Central.

【 图 表 】

Figure 1.

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