Increased yields of marine fish and shrimp production through application of innovative techniques with <i>Artemia</i>

The larval culture of fish and shrimp can be seriously improved thanks to the results of recent research and developments in the field of Artemia production and utilisation.The present article provides a historical overview of Artemia cyst demand and provision, summarizes the latest results of Artemia production in extensive and intensive culture systems and correlates the increased outputs in fish and shrimp hatcheries with improved applications of various Artemia products

The use of <i>Artemia</i> in marine fish larviculture

Among the live diets used in the larviculture of fish and shellfish, the brine shrimp Artemia nauplii constitute the most widely used food item; i.e., over 700 metric tons of dry Artemia cysts are annually marketed worldwide for on-site hatching into 0.4 mm nauplii.Although the use of Artemia appears to be simple, considerable progress has been made in the past decade in improving and increasing its value as a larval diet for marine fish larvae. The improvements include: identification of the most appropriate strains and batches; new techniques for cyst disinfection; decapsulation and hatching; and enrichment and cold storage of nauplii. Using particulate or emulsified products rich in highly unsaturated fatty acids or n-3 HUFAs, the nutritional quality of Artemia can be further tailored to suit the predators' requirements by bio-encapsulating specific amounts of these products in the Artemia metanauplii. Application of the method of bioencapsulation, also called Artemia enrichment or boosting, has had a major impact on larviculture output, not only in terms of survival, growth and success of metamorphosis of the fish, but also with regard to their quality, e.g., reduced malformations, improved pigmentation and increased stress-resistance. Nonetheless, in many species survival rates are still marginal.For several marine fish species, the optimal dietary levels of n-3 HUFAs are still not met by enriched Artemia . Furthermore, while n-3 HUFAs might have proven most critical, it is very likely that other nutrients (e.g., other lipid classes, vitamins and free amino acids) might appear equally important and in some species even more critical. The bio-encapsulation technique can also be used for the oral delivery of hormones and therapeutics to the fish larvae. Artemia juveniles, grown to a size that suits the feeding behaviour of the growing predator and/or adult biomass collected from local saltworks or mass production units, can be used as an excellent nursery and weaning diet for most species of marine fish, eventually reducing fish mortalities, cannibalism and heterogeneous growth

Low nutrient availability is not the single factor limiting <i>Artemia</i> cyst productivity in salinas of NE-Brazil

Artemia production in NE-Brazil began in 1977 after a successful inoculation of Artemia franciscana (San Fransisco Bay, California, USA) in solar salt ponds in Macau (RN state) and was followed by a rapid natural dispersion of this crustacean to all saltwork areas in the region. Artemia is basically produced in extensive conditions as an opportunistic by-product collected from salt evaporation ponds. This type of approach has, however, brought about very unpredictable results, as is reflected in a drastic decline of cyst production occurring from 1982 onwards. Low nutrient concentrations and a drop in primary productivity have been suggested as possible causes for this decline. In order to provide a better characterisation and understanding of these hypersaline environments, comparative ecological data were collected from artisanal salinas as well as highly mechanised salt operations. Artemia franciscana was present at all sites and was found to survive, mature, and reproduce at temperatures as high as 38°C. Cyst production in these biotopes was, however, negligible to low. In all studied habitats, nutrient levels (P-PO4; N-NO2; N-NO3) in medium to high salinity evaporation ponds showed little variation and were found to be low. Except for rain precipitation, little variation was found among biotypes for other parameters monitored (T°C; D.O.; pH; Salinity; Transparency).On the whole, Artemia cyst production seemed to be more dependent on simple management procedures, such as routine inoculations (nauplii and adults), rather than only on the low levels of nutrients found. It is postulated that Brazilian Artemia has gradually lost its ability for cyst reproduction as a result of (genetic?) adaptation to the year-round favourable conditions of the environment. Management strategies, including re-inoculation of a strain which has previously shown good cyst production characteristics (e.g., San Fransisco Bay or "old Macau") and application of salinity shocks, are proposed in order to revive cyst production in NE-Brazil

The use of brine shrimp <i>Artemia</i> in biological management of solar saltworks

In recent years, there has been a growing awareness of the hydrobiological aspects of the solar salt production process. Saltworks are man-managed artificial ecosystems that are highly vulnerable to biological disturbances, including uncontrolled proliferation of microalgae resulting in a reduced evaporation and contamination of the salt with gypsum and insoluble organic materials.Optimal production of solar salt, both in terms of quality and quantity, requires a well-established balance between the primary and secondary producers, with brine shrimp Artemia grazing on phytoplankton constituting the major interaction. In this paper, we discuss the beneficial role of Artemia in balancing the hydrobiological activity of the salt pond system and highlight some of the critical aspects essential to proper management of Artemia , including selection and controlled introduction of the most suitable strain of Artemia .Furthermore, the possibilities for establishing a vertically integrated aquaculture industry brought about by the opportunities for harvesting of Artemia cysts and biomass as valuable by-products of the solar salt operation will be discussed. Results of experiences gained in different projects around the world will be presented

Biological management to improve <i>Artemia</i> and salt production at Tanggu saltworks in the P.R. China

The worldwide distribution of the brine shrimp Artemia , in a variety of isolated biotopes with different ecological conditions, has resulted in the evolution of many geographical strains. Among these strains, substantial differences have been demonstrated in their nutritional quality and fitness, providing a basis for the selection of strains suitable for aquaculture. The Tanggu Saltworks (Tianjin, China) provide a unique environment for the production of Artemia . Unlike most other biotopes, they are characterized by a high primary productivity providing abundant food to sustain large populations of Artemia . Both laboratory studies and field observations, however, indicate that the local parthenogenetic Artemia strain has a low productivity (especially at lower temperatures) and a poorer resistance to high salinities than bisexual A. franciscana strains. Moreover, the particular climatological conditions of the Tanggu region tend to retard the natural colonization of the saltworks in spring, which may result in suboptimal hydrobiological conditions for salt production. In this paper, we propose a biological management plan involving controlled introduction of a selected Artemia strain with optimal productivity, and discuss possibilities to upgrade salt and Artemia production qualitatively and quantitatively

Roles and potentials of <i>Artemia</i> in coastal saltworks

The recent developments in aquaculture production of fish and shrimp have resulted in increased demands for Artemia cysts and biomass as valuable sources of life food. Solar salt works are suitable biotopes for the integrated exploitation of salt, Artemia and eventually fish or shrimp. Artemia may be present as a natural resource in local saltworks; however in some situations characteristics of the endemic strain might justify the introduction of another Artemia species to increase productivity