Genetics and disease resistance in aquaculture

Abstract

Disease in aquaculture is a significant problem especially in intensive culture systems. Relatively little effort in combating disease has been expended in developing genetically resistant strains. Nevertheless, the experience available from economically important terrestrial species, the need to use environmentally friendly or neutral production systems and the impressive range of genetic technologies available, combine to suggest that genetic approaches to disease resistance (combined with appropriate husbandry) represent the most effective and attractive way forward.

Application of α-glucosidase activity and drug susceptibility tests to epidemiological studies on the fish pathogen Nocardia seriolae

“…One of the important consequences of using antibiotics in aquacultural systems is the considerable selection pressure that confers drug resistance to the target and other pathogenic species [14]. Recently, Itano and Kawakami [15] reported that some strains of N. seriolae are resistant to both OTC and Em.…”

Genetic improvement in the Australian aquaculture industry

“…Ranking refers to the number of groups (out of four) that considered the strategy to be a priority. Concerns over hatchery production and disease resistance arose from the recognition that disease still poses a signi®cant problem for aquaculture, especially in intensive culture systems (Beardmore & McConnell 1998;Nell, Smith & McPhee 1999). Table 3 lists the areas considered to be research priorities.…”

“…The recommendation to assess wild genetic resources re¯ects the ®nding that wild stocks from different geographic areas often show differences in performance traits (Kinghorn 1983;Fetzner, Sheehan & Seeb 1997;Knibb et al 1998). Concerns over hatchery production and disease resistance arose from the recognition that disease still poses a signi®cant problem for aquaculture, especially in intensive culture systems (Beardmore & McConnell 1998;Nell, Smith & McPhee 1999).…”

“…For most species, the recommended selection criterion for this trait was body weight or body size at harvest. Disease resistance, as a separate trait to survival, was considered very important in some species, but useable selection criteria have not yet been widely developed (Beardmore & McConnell 1998). Survival to harvest, while not considered as important as size, was included in the breeding objectives of all groups.…”

A risk analysis framework for aquatic animal health management in marine stock enhancement programmes

“…Specific strains of fish may be resistant to certain pathogens as in the case of Atlantic salmon, where populations from the Baltic Sea are resistant to the salmon parasite, Gyrodactylus salaris, whereas Atlantic stocks in Norway are susceptible (Bakke et al, 1990). Allelic diversity appears to be correlated with general disease resistance (Beardmore and McConnell, 1998). Although breeding for disease resistance is an important part of many commercial aquaculture ventures, it may not be efficient in stock enhancement programmes because selection usually reduces overall genetic variability.…”