Abstract
The search for alternative live feed organisms and the progression of Integrative Multi-Trophic Aquaculture (IMTA) are currently being highly prioritised in EU strategies. Caprellids could potentially be an important exploitable resource in aquaculture due to their high levels of beneficial polyunsaturated fatty acids, fast growing nature and widespread distribution. Furthermore, since they are mainly detritivorous, they could be excellent candidates for integration into IMTA systems, potentially benefitting from uneaten feed pellets and faeces released by cultured fish in fish farms and sea-cage structures. Despite this, there is a lack of experimental studies to: (i) test inexpensive diets for caprellids, such as detritus, (ii) develop sustainable caprellid culture techniques and (iii) include caprellids in IMTA systems. The main aim of this study was to determine whether detritus (D) in the form of fish faeces provided an adequate diet for caprellids in comparison to other traditional diets, such as Artemia nauplii (A) or phytoplankton (P). Adult survival rate was shown to be significantly higher for caprellids fed with D. Conversely, hatchlings had the highest survival rate with A, although the juvenile growth rate and number of moults was similar in the three diets. With regard to lipid composition, caprellids fed with A had higher concentrations of Triacylglycerols (TAG) and Phosphatidylcholine (PC) while those fed with P or D were richer in polyunsaturated fatty acids, especially 22:6(n-3) (DHA). Interestingly, caprellids fed with D were also a rich source of 18:2(n-6) (LA), considered to be an essential fatty acid in vertebrates. It was found that detritus based mainly on fish faeces and uneaten feed pellets can be considered an adequate feed for adult caprellids, providing a source of both omega-3 (DHA) and omega-6 (LA) fatty acids. Hatchlings however seem to require an additional input of TAG and PC during juvenile stages to properly grow.
Highlights
Aquaculture accounts for nearly 40% of fin- and shellfish consumed worldwide, reaching 62.7 million tonnes in 2011 [1]
Integrated Multi-Trophic Aquaculture’ (IMTA) involves the integrated cultivation of fed species together with extractive species which feed on detritus from the fed species [1]
It has been demonstrated that macroinvertebrate fauna present in fouling communities can take up sinking organic matter from fish farms and sea-cage structures, benefitting from uneaten feed pellets and faeces from the cultured fish [12,13]
Summary
Aquaculture accounts for nearly 40% of fin- and shellfish consumed worldwide, reaching 62.7 million tonnes in 2011 [1]. In the framework of the innovative research programmes in aquaculture there are currently two areas of increasing interest: (i) the search for alternative live feed organisms, and (ii) the progress in ‘Integrated Multi-Trophic Aquaculture’ (IMTA). (ii) A number of methods to increase production levels in aquaculture have attracted attention, such as offshore aquaculture installations [8], recirculating aquaculture systems [9], and especially the innovative technology IMTA [10]. Along with improving effluent management, IMTA approaches reduce waste, diversify products, improve the economics, expand the range of suitable development sites and increase the biosecurity of farms ([14] and references therein). IMTA could become an integral part of coastal regulatory and management frameworks, with the challenge being the establishment of safe and stable systems with an economically feasible output [3, 16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
