The authors performed a study to determine the tolerance of shrimp postlarvae to the crowding effects of high-density stocking in terms of production performance. Postlarvae were stocked in heavily aerated microcosm tanks with biofloc at 1,500; 3,000; 6,000 or 9,000 shrimp/m3. High survival was observed at all densities. Final biomass values increased with higher stocking densities, but there was no significant difference between the 6,000 and 9,000 shrimp/m3 treatments or the 1,500 and 3,000 shrimp/m3 treatments.
The benefits realized by recirculating aquaculture systems – including enhanced fish growth, product quality and survival, as well as reduced treatment costs – have made the RAS approach an important production trend.
Real-time, quantitative polymerase chain reaction (qPCR) analysis has become an attractive alternative for quantification of the acute hepatopancreatic necrosis disease (AHPND) pathogen in infected shrimp. The authors developed a qPCR assay to quantify a virulence plasmid harbored by the bacterium that causes AHPND.
The bacterium Flavobacterium columnare and parasite Ichthyophthirius multifiliis (Ich) are common pathogens that can cause heavy economic losses for fish culture. The authors conducted a study to evaluate the susceptibility of hybrid tilapia to F. columnare, including fish mortality and bacterial numbers in fish after parasitism by Ich.
A preliminary study investigated the effects of diet on the meat quality and shell color of Pacific abalone. A test diet and a commercial abalone feed resulted in lower meat protein content compared to that achieved with a diet of Pacific dulse seaweed. The artificial diets also caused the abalone to have yellow or orange shells. The seaweed diet alone resulted in abalone with dark-brown shells. However, a combination of seaweed and either artificial diet improved abalone growth, meat quality and shell color.
The authors performed a study to assess the plankton community in an integrated biofloc system with Pacific white shrimp (Litopenaeus vannamei) and red algae (Gracilaria birdiae).
A National Broodstock Improvement Network for aquaculture could help to break the link between inbreeding and hatchery size.
Vibrio infections are an increasingly common problem in intensive shrimp culture. As evidenced by study results, weekly Vibrio monitoring can be a useful tool for predicting bacterial disease outbreaks.
Seasonal pathologies reduce the profitability and sustainability of the shrimp-farming industry in New Caledonia. A study was therefore conducted to estimate the effects of polyculture of blue shrimp with goldline rabbitfish or mullet on production performance and environmental quality.
If an animal is stressed, its immune function decreases, and vulnerability to diseases increases. Since there is currently no effective treatment for disease in echinoderms, the authors examined the impacts of handling and salinity fluctuations on the immune functions of sea cucumbers and sea urchins.
The maturation of Atlantic salmon prior to harvest is costly, so since male salmon are more likely to mature early, the salmon industry in Tasmania relies on all-female production.
Escapes of fish from farm facilities can lead to interbreeding and competition for mating opportunities with wild fish. Escapees may also transmit diseases and parasites, as well as compete for feed and space.
Investing in the quality of shrimp postlarvae by applying state-of-the-art hatchery management results in a significant return on investment. Nutrition and health protocols have large impacts on postlarvae quality that last beyond the early life stages.
The summer season poses threats for oyster aquaculture worldwide. In addition to high mortality, poor oyster quality and health – especially in enclosed bays – are often attributed to water stratification, high temperatures and hypoxia.
Research at a hatchery in Mozambique has demonstrated the possibility of developing acquired immunity to white spot syndrome virus within shrimp. The approach involves activating the immune system via a specific manipulation of water parameters during the treatment, intensity level and timing, with the secondary help of immunostimulants.
Enterocytozoon hepatopenaei (EHP), a microsporidian parasite widely found in Asia and other areas, is impacting aquaculture by severely retarding the growth of cultured shrimp. EHP infects the tubules of the hepatopancreas in shrimp, which damages the organ’s ability to gain nutrition from feed.