Limits...
Feeding preferences and the nutritional value of tropical algae for the abalone Haliotis asinina.

Angell AR, Pirozzi I, de Nys R, Paul NA - PLoS ONE (2012)

Bottom Line: Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed.Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant.The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties.

View Article: PubMed Central - PubMed

Affiliation: School of Marine and Tropical Biology & Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Australia. alex.angell@my.jcu.edu.au

ABSTRACT
Understanding the feeding preferences of abalone (high-value marine herbivores) is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae--or any feedstock--which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid content of algae have rarely been simultaneously investigated for abalone, and never for the emerging target species Haliotis asinina. Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed. For example, preferred Hypnea and Ulva had distinctly different protein contents (12.64 vs. 2.99 g 100 g(-1)) and the protein-rich Asparagopsis taxiformis (>15 g 100 g(-1) of dry weight) was one of the least preferred algae. The limiting amino acid in all algae was methionine, followed by histidine or lysine. Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant. The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties.

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No-choice feeding assay for the 8 species of algae used in the previous choice assays.Data show mean (+SE) consumption rates (g FW algae day−1, n = 5) of algae per treatment standardised for abalone size (100g−1 BW). Abalone size ranged from 30–186 g (mean = 94.73 g). Common letters above columns indicate no significant difference (Tukey’s HSD, p>0.05).
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pone-0038857-g002: No-choice feeding assay for the 8 species of algae used in the previous choice assays.Data show mean (+SE) consumption rates (g FW algae day−1, n = 5) of algae per treatment standardised for abalone size (100g−1 BW). Abalone size ranged from 30–186 g (mean = 94.73 g). Common letters above columns indicate no significant difference (Tukey’s HSD, p>0.05).

Mentions: Data show means (±SE) for all indices. Dry weight consumption rates of algae (g 100 g−1 BW day−1) were calculated using wet:dry ratio (cf. Fig 2, fresh weight consumption of algal diets). Dry weight consumption rates of algae bound by carrageenan into artificial diets presented (cf. Fig. 3 fresh weight consumption of artificial diets). Carbon to nitrogen (C:N) ratio, protein content (g 100 g−1 DW: calculated as the sum of amino acids from Table 1), and essential amino acid index are presented. The effective protein content (g 100 g−1 DW: adjusted for the limiting amino acid from Table 1) and the effective protein consumption rate in the algal no-choice feeding assay (Fig. 2) are also presented. Common letter superscripts indicate no significant difference (ANOVA, Tukey’s HSD, p>0.05).


Feeding preferences and the nutritional value of tropical algae for the abalone Haliotis asinina.

Angell AR, Pirozzi I, de Nys R, Paul NA - PLoS ONE (2012)

No-choice feeding assay for the 8 species of algae used in the previous choice assays.Data show mean (+SE) consumption rates (g FW algae day−1, n = 5) of algae per treatment standardised for abalone size (100g−1 BW). Abalone size ranged from 30–186 g (mean = 94.73 g). Common letters above columns indicate no significant difference (Tukey’s HSD, p>0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3375308&req=5

pone-0038857-g002: No-choice feeding assay for the 8 species of algae used in the previous choice assays.Data show mean (+SE) consumption rates (g FW algae day−1, n = 5) of algae per treatment standardised for abalone size (100g−1 BW). Abalone size ranged from 30–186 g (mean = 94.73 g). Common letters above columns indicate no significant difference (Tukey’s HSD, p>0.05).
Mentions: Data show means (±SE) for all indices. Dry weight consumption rates of algae (g 100 g−1 BW day−1) were calculated using wet:dry ratio (cf. Fig 2, fresh weight consumption of algal diets). Dry weight consumption rates of algae bound by carrageenan into artificial diets presented (cf. Fig. 3 fresh weight consumption of artificial diets). Carbon to nitrogen (C:N) ratio, protein content (g 100 g−1 DW: calculated as the sum of amino acids from Table 1), and essential amino acid index are presented. The effective protein content (g 100 g−1 DW: adjusted for the limiting amino acid from Table 1) and the effective protein consumption rate in the algal no-choice feeding assay (Fig. 2) are also presented. Common letter superscripts indicate no significant difference (ANOVA, Tukey’s HSD, p>0.05).

Bottom Line: Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed.Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant.The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties.

View Article: PubMed Central - PubMed

Affiliation: School of Marine and Tropical Biology & Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Australia. alex.angell@my.jcu.edu.au

ABSTRACT
Understanding the feeding preferences of abalone (high-value marine herbivores) is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae--or any feedstock--which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid content of algae have rarely been simultaneously investigated for abalone, and never for the emerging target species Haliotis asinina. Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids) and preference existed. For example, preferred Hypnea and Ulva had distinctly different protein contents (12.64 vs. 2.99 g 100 g(-1)) and the protein-rich Asparagopsis taxiformis (>15 g 100 g(-1) of dry weight) was one of the least preferred algae. The limiting amino acid in all algae was methionine, followed by histidine or lysine. Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant. The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties.

Show MeSH