Effects of wild and farm-grown macroalgae on the growth of juvenile South African abalone Haliotis midae Linnaeus

  • DV Robertson-Andersson
  • GW Maneveldt
  • K Naidoo

Abstract

The effect of various macroalgal diets on the growth of grow-out (>20 mm shell length) South African abalone Haliotis midae was investigated on a commercial abalone farm. The experiment consisted of four treatments: fresh kelp blades (Ecklonia maxima (Osbeck) Papenfuss) (c. 10% protein); farmed, protein-enriched Ulva lactuca Linnaeus (c. 26% protein) grown in aquaculture effluent; wild U. lactuca (c. 20% protein); and a combination diet of kelp blades + farmed U. lactuca. Abalone grew best on the combination diet (0.423 ± 0.02% weight d−1 SGR [specific growth rate]; 59.593 ± 0.02 μm d−1 DISL [daily increment in shell length]; 1.093 final CF [condition factor]) followed by the kelp only diet (0.367 ± 0.02% weight d−1 SGR; 53.148 ± 0.02 μm d−1 DISL; 1.047 final CF), then the farmed, protein-enriched U. lactuca only diet (0.290 ± 0.02% weight d−1 SGR; 42.988 ± 0.03 μm d−1 DISL; 1.013 final CF) that in turn outperformed the wild U. lactuca only diet (−0.079 ± 0.01% weight d−1 SGR; 3.745 ± 0.02 μm d−1 DISL; 0.812 final CF). The results suggest that protein alone could not have accounted for the differences produced by the varieties of U. lactuca and that the gross energy content is probably important.

Keywords: Ecklonia maxima, farm-grown, growth, mixed diet, protein content, Ulva lactuca

African Journal of Aquatic Science 2011, 36(3): 331–337

Author Biographies

DV Robertson-Andersson
Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
GW Maneveldt
Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
K Naidoo
Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
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Articles

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eISSN: 1727-9364
print ISSN: 1608-5914