Search

Improving feed suitability and bolstering the global upsurge in fish production is a strategic challenge for aquaculture. The utilization of plant and animal derived ingredients in aquafeed for achieving sustainable in finfish aquaculture is affected by various factors, including the presence of antinutritional factors, lowered nutrient bioavailability, indigestible particles and microbial contaminants. Applying fermentation to overcome these problems in aquafeed ingredients has received considerable attention in recent years as fermentation provides health‐promoting probiotic benefits to host organisms. Fermentation has also been shown in many studies to improve nutrient availability and bioavailability of feed, increased palatability and digestibility and eliminate anti‐nutritional compounds in dietary feed ingredients, making them more easily digestible which eventually improve growth and health performance of fish. Therefore, it is imperative to accelerate the use of fermented feedstuffs as aquafeed if sustainable aquaculture is to be achieved. This review reported the various methods of fermentation, characteristics of fermented feed ingredients, factors that are considered during fermentation and overall nutritional quality of fermented feed ingredients for aquaculture production. The role of fermented feed ingredients for various farmed species in terms of growth, feed utilization, gut microbiota composition, immunity and disease resistance in fish is thoroughly discussed. The possible drawbacks associated with the fermentation process are also discussed in the article. [ABSTRACT FROM AUTHOR]

Utilising novel ingredients in aquafeeds is necessary for the continued expansion and intensification of aquaculture production. Microalgae are utilised widely in aquaculture for a variety of purposes; as live feed for fish and shellfish larvae and juveniles, for the production of algae‐based meals and oils to replace marine derived raw materials in aquafeeds, and for the production of astaxanthin, the carotenoid that gives salmon flesh its characteristic reddish colour. Notably, long‐chain polyunsaturated fatty acids, amino acids, proteins, fibres, antioxidant pigments, vitamins and minerals are among the compounds in microalgae with great biological value. A growing collection of experimental data has demonstrated that these substances are crucial for increasing larval survival and enhancing the growth and well‐being of fish and shellfish. In this review, the processing of microalgae utilised as aquafeed ingredient, the health promoting compounds in microalgae and their role in growth, immunity and disease resistance of fish and shellfish are described and discussed. Simultaneously, major hurdles in the commercial use of microalgae in aquafeed, and future research and development perspectives are all critically discussed. [ABSTRACT FROM AUTHOR]

The aims of this review are to describe the role of 'blue‐food production' (animals, plants and algae harvested from freshwater and marine environments) within a circular bioeconomy, discuss how such a framework can help the sustainability and resilience of aquaculture and to summarise key examples of novel nutrient sources that are emerging in the field of fed‐aquaculture species. Aquaculture now provides >50% of the global seafood supply, a share that is expected to increase to at least 60% within the next decade. Aquaculture is an important tool for reducing resource consumption in global protein production and increasing resilience to climate change and other global disruptions (i.e. pandemics, geo‐political instability). Importantly, blue foods also provide essential nutrition for a growing human population. Blue foods are helping to help the global goal of 'zero hunger' (United Nation's Sustainable Development Goal 2) while reducing the dependency on finite natural resources but further refinement and new solutions are needed to make the industry more 'circular' and sustainable, particularly with respect to sourcing raw materials for aquafeeds. This review describes the feed resources that are available or may be created within a circular bioeconomy framework, their role within the framework and in aquaculture and ultimately, how these resources contribute to de‐risking and establishing a resilient aquaculture production chain. [ABSTRACT FROM AUTHOR]

The flavour of aquatic animal products is distinct from terrestrial foods, facilitating a competitive marketing advantage. However, the flavour of aquatic animals can also be highly variable. Importantly, differences are reported in the flavour of animals from aquaculture and wild‐capture systems. These differences can erode consumer acceptance of aquaculture products and reduce financial returns to producers. Mild 'fish‐like', 'marine', 'crustacean‐like', 'seafood' and 'sweet' odours are desirable. However, overt 'fish‐like', 'fatty' and 'earthy' odours are quality deficits and cause products to become unpalatable. Odorous volatile compounds are responsible for eliciting these characteristic odours. In this literature review, the odorous volatile compounds of 96 aquatic animal samples are reported, revealing 291 different compounds. Generalist compounds that are integral to the odour of aquatic animals are presented in addition to 86 compounds that elicit key characteristic odours. The influence of these compounds on aquatic animal flavour is explored and the specific factors likely to affect their manipulation in aquaculture products are discussed. The culture environment and diet are critical factors affecting volatile profiles of aquatic animals and are the variables that can be controlled by aquaculture producers. The information presented in this review can underpin the development of innovative aquaculture strategies that prevent environmental exposure of aquatic animals to unpalatable volatile compounds and facilitate the development of aquaculture diets that optimise the volatile profile of edible tissues. [ABSTRACT FROM AUTHOR]

Abstract: Ocean warming (OW) and ocean acidification (OA) are threatening coral reef ecosystems, with a bleak future forecast for reef‐building corals, which are already experiencing global declines in abundance. In contrast, many coral reef sponge species are able to tolerate climate change conditions projected for 2100. To increase our understanding of the mechanisms underpinning this tolerance, we explored the lipid and fatty acid (FA) composition of four sponge species with differing sensitivities to climate change, experimentally exposed to OW and OA levels predicted for 2100, under two CO2 Representative Concentration Pathways. Sponges with greater concentrations of storage lipid, phospholipids, sterols and elevated concentrations of n‐3 and n‐6 long‐chain polyunsaturated FA (LC PUFA), were more resistant to OW. Such biochemical constituents likely contribute to the ability of these sponges to maintain membrane function and cell homeostasis in the face of environmental change. Our results suggest that n‐3 and n‐6 LC PUFA are important components of the sponge stress response potentially via chain elongation and the eicosanoid stress‐signalling pathways. The capacity for sponges to compositionally alter their membrane lipids in response to stress was also explored using a number of specific homeoviscous adaptation (HVA) indicators. This revealed a potential mechanism via which additional CO2 could facilitate the resistance of phototrophic sponges to thermal stress through an increased synthesis of membrane‐stabilizing sterols. Finally, OW induced an increase in FA unsaturation in phototrophic sponges but a decrease in heterotrophic species, providing support for a difference in the thermal response pathway between the sponge host and the associated photosymbionts. Here we have shown that sponge lipids and FA are likely to be an important component of the sponge stress response and may play a role in facilitating sponge survival under future climate conditions. [ABSTRACT FROM AUTHOR]

The closed-cycle rearing of palinurid lobsters in commercially relevant quantities currently represents one of the most difficult challenges facing modern-day aquaculture. The length and complexity of the larval life cycle exacerbate the problem, comprising the major bottleneck to their successful aquaculture. The general consensus is that developments in the key research area of nutrition will provide the necessary breakthroughs to make the closed-cycle rearing of lobster a reality. Due to the cryptic nature of feeding preferences and complex larval morphology, a commercially formulated feed for their culture does currently not exist. Nevertheless, there has been a wealth of research conducted to elucidate many of the unknowns concerning larval nutritional requirements. This review presents a synthesis of this information, ranging from investigations of larval morphology and feeding behaviour, hatchery nutrition practices, the elucidation of wild prey items and the nutritional content of wild-caught larval species. Based on the information available, this review culminates with a 'best guess' formulation for a larval spiny lobster diet, taking aspects concerning both the physical and chemical attributes of formulation into consideration. It is concluded that larval spiny lobsters are likely comparatively low in relation to other larval species with respect to their quantitative dietary requirements. Ultimately, the overall success of the larval cycle appears to be dictated by the stockpiling of lipids to fuel an energy-demanding metamorphosis and a subsequent nonfeeding puerulus phase. These insights provide valuable direction for the formulation of nutritionally complete feeds to permit the closed-loop culture of spiny lobster species. [ABSTRACT FROM AUTHOR]