Aquaculture waste as food for amphipods: the case of Gammarus insensibilis in marsh ponds from southern Spain

Abstract

Amphipods are emerging as an alternative food resource for fishes and cephalopods in aquaculture. Gammarus insensibilis (Stock, 1996), one of the dominant amphipods inhabiting marsh ponds in southern Spain, has been recently proposed as a promising candidate for being intensively cultured due to its adequate nutritional profile, large body size, and high natural densities. The main aim of this study was to determine whether waste products of aquaculture (such as detritus in the form of fish feces or Ulva sp.) provided an adequate diet for the amphipod in comparison to other traditional diets, such as Artemia nauplii or phytoplankton. G. insensibilis was cultured twice in tanks with 5 treatments: 4 experimental diets (detritus, Ulva sp., Artemia nauplii, and phytoplankton) were used, and one no-feed treatment. Amphipods fed with the two alternative diets, detritus and Ulva, showed promising survival higher than 40% and high concentrations of palmitic acid (16:0), oleic acid (18:1n9), arachidonic acid (20:4n6) (ARA), eicosapentaenoic acid (20:5n3) (EPA), and docosahexaenoic acid (22:6n3) (DHA). Therefore, large-scale culture of this amphipod using inexpensive diets in indoor facilities could provide a nutritious product for aquaculture. The potential development of a sustainable culture using this species in marsh ponds is also discussed in the context of Integrated Multi-Trophic Aquaculture (IMTA).