Bioactive Compounds Offered in Microcapsules to Determine the Nutritional Value of Copepods’ Natural Diet

Abstract

Experiments were performed, feeding Calanus pacificus seston and a food consisting of seston and microcapsules (μ-caps), i.e., protein and lipid μ-caps to test for potential biochemical limitation. Seston was collected off Scripps Pier (La Jolla, CA, USA). Whereas protein μ-caps were too small to be efficiently ingested, lipid μ-caps rich in ω3-highly-unsaturated fatty acids (ω3-HUFA) were ingested similarly to natural seston and lipids were assimilated. However, egg production experiments exhibited that animals fed with lipid μ-caps didn’t produce significantly more eggs than with seston of equal carbon concentration and egg production even declined when the diet consisted of 50% lipid μ-caps. Thus, the content of certain ω3-HUFA seemed to have been sufficiently high in seston to prevent limitation. Algal counts revealed that seston consisted mainly of plankton rich in those fatty acids, such as cryptophytes, dinoflagellates, diatoms, and ciliates in the edible size range. This might be characteristic for upwelling systems like the area off Southern California which are known for high trophic transfer efficiency.

Seasonal variation and species-specific concentrations of the essential vitamin B1 (thiamin) in zooplankton and seston

“…Food quality is often defined by fatty acid content and composition (Ahlgren et al 1992;Müller-Navarra and Huntley 2013). Reduced levels of specific fatty acids have been shown to not only negatively affect zooplankton growth rates and fecundity, but also affecting the transfer of carbon in the food web (Müller-Navarra et al 2000).…”

“…The nutritional value of zooplanktons and their food items is often assessed by the composition and concentration of fatty acids (Ahlgren et al 1992(Ahlgren et al , 2005Müller-Navarra and Huntley 2013). While the effect of fatty acid content on zooplankton reproductive success have received much attention (Brett et al 2009;Jónasdóttir 1994;Jónasdóttir and Kiørboe 1996), vitamin content and transfer in the aquatic food web has been largely neglected.…”

Food quality matters: Interplay among food quality, food quantity and temperature affecting life history traits of Aurelia aurita (Cnidaria: Scyphozoa) polyps

“…Thus, alterations of HUFA in primary producers will consequently alter herbivores' growth and reproduction via changing community structure and bio-chemicals composition (Jónasdóttir, 1994;Müller-Navarra and Huntley, 2013). The same processes will potentially affect development at higher trophic levels, such as fishes (e.g., Sargent et al, 2002).…”