30 March 2009 Identification and control of parasites in a new species for aquaculture: A case study with striped trumpeter, Latris lineata M. Andrews1, B. Nowak2, J.M. Cobcroft1 and S.C. Battaglene1 Our studies are taking place in Tasmania, Australia’s southern most island state situated directly on the ‘roaring forties’, which has a very changeable weather pattern throughout the year with snowfalls not uncommon in summer. This cool to mild climate is ideal for temperate agriculture and aquaculture. The Tasmanian aquaculture industry began in the mid-1940s with the cultivation of Pacific oysters. It has since expanded to include other shellfish, such as abalone, scallops and mussels. Today the largest Tasmanian aquaculture industry involves the production of over 18,000 t of Atlantic salmon per year in sea cages. Since the beginning, the salmon industry has experienced various health challenges, including amoebic gill disease (AGD). Treatment of this disease using freshwater is relatively simple but expensive and progress is being made in the development of a vaccine. Atlantic salmon are also reared at sea temperatures close to their thermal maximum in late summer and it makes sense for the industry to diversify into other marine species. The industry is particularly interested in developing an alternative native white-fleshed fish species. Striped trumpeter, Latris lineata, was identified in the 1980s as a possible aquaculture species because of its tolerance to handling, high stocking density as well as superior flesh quality, which is high in omega-3 fatty acids and highly regarded as sashimi (Nichols et al. 2005). Striped Trumpeter: An Overview The striped trumpeter is a very interesting species with an unusual life history that includes a protracted postlarval stage and, until very recently, little Fig. 1. Adult striped trumpeter at the Marine Research Laboratories, Tasmania was known of its biology (Tracey and Lyle 2005). The fish used to be plentiful, however the population is currently depleted because of the combined effects of fishing and several years of poor recruitment. The wild population will not be able to support higher levels of catch, therefore, aquaculture is seen as the best option to provide striped trumpeter in greater quantity. The species is common around Tasmania, the more southern waters of mainland Australia and around New Zealand and some islands in the Indian Ocean. They are typically found in water ranging between 11 and 18°C and spawn in Tasmanian waters between July and October, depending on latitude (Tracy and Lyle 2005). Adults live in deep water and can reach 1.2 m with sexual maturity reached at 5-6 years of age (Figure 1). Research into the culture of striped trumpeter started in earnest in the 1990s with early emphasis being placed on the reproductive cycle, including broodstock management and egg incubation. Another very important aspect of the project was to develop techniques to improve the survival and quality of the early life stages by developing more efficient hatchery and incubation methods (Morehead and Hart 2003). Despite much research, the species has proven difficult to culture and only recently has reliable hatchery production been achieved following extensive research into nutrition and control of bacteria (Bransden et al. 2005, Battaglene et al. 2006). These studies have helped overcome many of the problems experienced in larval rearing and the first sea cage trials are planned at the time of this writing. Aquaculture and the Problem of Diseases and Parasites It is a widely accepted that diseases and parasites pose a major problem to aquaculture, with a variety of cultivated marine and freshwater species being affected globally. Examples of problem parasites are the copepods affecting the culture of Atlantic salmon and sea trout in the northern hemisphere, AGD in Atlantic salmon in Australia and the monogenean that affects the tiger puffer in Japan (Hirazawa et al. 2003). Emerging new species are particularly vulnerable as can be seen with yellowtail kingfish, Seriola lalandi, in Australia that are affected by the monogenean Benedenia seriolae, which causes reduced growth, poor carcass quality and increased mortalities (Chambers and Ernst 2005). An-
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