Diet rather than temperature determines the biochemical composition of the ragworm Hediste diversicolor (OF Müller, 1776) (Annelida: Nereidae)

Arne M. Malzahn*, Andrea Villena-Rodríguez, Óscar Monroig, Åsmund Johansen, L. Filipe C. Castro, Juan C. Navarro, Andreas Hagemann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


The polychaete Hediste diversicolor is known to recycle side streams from aquaculture and biogas production. We conducted a feeding experiment to evaluate whether rearing temperature or mixtures of these two side streams enhances biomass production and fatty acid composition. We reared H. diversicolor along a 5-temperature gradient ranging from 5.8 °C to 17.1 °C and a 4-step gradient form 100% aquaculture sludge to 100% solid biogas digestate. Formulated fish feed served as a control diet. Polychaetes increased growth rate with increasing temperature, ranging from 0.01 at 5.8 °C to 0.14 at 17.1 °C, while survival was inversely affected by temperature with 100% survival at 5.8 °C and 70% survival at 17.1 °C. Diet had a less pronounced effect on polychaete survival, and no significant effect on growth rates. Contrasting to growth, the fatty acid composition of the polychaetes was not affected by temperature but was highly influenced by diet, as polychaetes did not cluster by rearing temperature but by the diets they received. In conclusion, H. diversicolor can be utilized as a recycler of aquaculture and biogas side streams, and production temperature can be optimized for growth without compromising fatty acid composition and quality of the polychaetes.

Original languageEnglish
Article number739368
Publication statusPublished - May 15 2023


  • Aquaculture waste
  • Aquafeed
  • Bioremediation
  • Circular economy
  • Fatty acids
  • Homeoviscous adaptation
  • Nutrient recycling
  • Salmon aquaculture
  • Side streams
  • Solid biogas digestate

ASJC Scopus subject areas

  • Aquatic Science

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