Susceptibility of Triploid Rainbow Trout to IHN, Furunculosis and Vibriosis.

Abstract

Triploid rainbow trout was compared with diploid one for the susceptibility to IHN, furunculosis and vibriosis, and for the effectiveness of vibrio vaccination.No differ ence was observed between the triploids and the diploids in the mortality or in the mean days to death when challenged with the pathogens of the diseases. Vaccinated triploids showed significantly lower mortality than triploids without vaccination when challenged with Vibrio ordalii, and there was no difference in the mortality between vaccinated dip loids and triploids. These results suggest that susceptibility to those infections and effectiveness of vibrio vaccination are principally the same for both diploid and triploid rain bow trout.

High Gyrodactylus salaris infection rate in triploid Atlantic salmon Salmo salar

“…As a result, it may take a longer time to recover complement activity for triploid salmon (Langston et al 2001). This is also in accordance with earlier studies that have demonstrated elevated susceptibility of triploid salmonids to various viral or bacterial pathogens (Yamamoto & Iida 1994, 1995, Jhingan et al 2003, Dunham 2004. However, triploidy of the host does not always result in increased parasite abundance, as similar susceptibility to Gyrodactylus sp.…”

“…However, several studies have failed to de-tect significant differences in susceptibility between diploid and triploid fish. For example, both diploid and triploid rainbow trout exposed to Vibrio ordalii, Aeromonas salmonicida, or infectious hematopoietic necrosis virus demonstrated similar mortality rates (Yamamoto & Iida 1995). Similar mortality rates between diploid and triploid Atlantic salmon were also observed after experimental infection with Renibacterium salmoninarum (Bruno & Johnstone 1990).…”

The kinetics of the hypoferraemic response and changes in levels of alternative complement activity in diploid and triploid Atlantic salmon, following injection of lipopolysaccharide

“…This has also been shown to be the case in other species of fish (Kusuda et al, 1991;Yamamoto & Iida, 1995a). The comparative susceptibility to diseases of diploid and triploid fish is still debated, but the majority of published literature shows *Corresponding author.…”

Transcriptional differences between triploid and diploid Chinook salmon (Oncorhynchus tshawytscha) during live Vibrio anguillarum challenge

“…Triploid Chinook salmon generally exhibit a normal phenotype with few differences from diploid salmon at resting-state (reviewed by Benfey, 1999), although, in seawater trials, survivability of triploid salmonids has generally been lower than that of diploids (O'Flynn et al, 1997;Benfey, 2001;Cotter et al, 2002), suggesting a difference in disease resistance. However, studies on the immunocompetence of triploid salmonids have proven equivocal (reviewed by Bruno and Johnstone, 1990;Yamamoto and Iida, 1995;Benfey, 1999), but the inconsistent results may be because of individual and familial variation or genotype-by-environmental interactions, not ploidy differences (Johnson et al, 2004(Johnson et al, , 2007Miller et al, 2004). Immune challenge studies with a variety of pathogens resulted in either equal competence of triploid and diploid fish, or triploids faring poorly relative to diploids (Bruno and Johnstone, 1990;Dorson et al, 1991;Ojolick et al, 1995;Johnson et al, 2004).…”