Feeding Preferences and the Nutritional Value of Tropical Algae for the Abalone Haliotis asinina

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.

The developmental biogeography of hawksbill sea turtles in the North Pacific

“…For algae, we converted dry to wet volume assuming 86.5% water content (Angell et al. ). For plastic debris, we counted the total pieces, recorded their color, and measured their length and width dimensions (Bugoni et al.…”

“…After weighing, we stored each group in graduated 1.5 mL cryovials (Thermo Fisher Scientific TM , Waltham, Massachusetts, USA Nalgene TM ), recording the dry volume. For algae, we converted dry to wet volume assuming 86.5% water content (Angell et al 2012). For plastic debris, we counted the total pieces, recorded their color, and measured their length and width dimensions (Bugoni et al 2001;Mascarenhas et al 2004;Lazar and Gra can 2011) with a Greenough stereomicroscope (scope: Leica TM S8 APO, camera: Leica TM DFC295, firmware: Leica TM Microsystems, Buffalo Grove, Illinois, USA Applications Suite).…”

Biochemical evolution in response to intensive harvesting in algae: Evolution of quality and quantity

“…As asparagine is hydrolysed to aspartic acid and glutamine to glutamic acid during analysis, the sum of these amino acids was reported as asparagine/aspartic acid or glutamic acid/glutamine. Cysteine tryptophan and taurine were not analysed as these require different analytical methods and represent only a very small fraction (<2%) of the total amino acids present in green macroalgae (Angell, Mata, de Nys, & Paul, 2014; Angell, Pirozzi, De Nys, & Paul, 2012). The amino acid productivities (g DW m −2  day −1 ) of each strain were calculated for each treatment by multiplying the DW productivity of each replicate from week 12 and 16 of the experiment by its amino acid content (mg g algal/DW).…”

Abalone growth and associated aspects: now from a metabolic perspective

“…; Bautista‐Teruel & Millamena ; Angell et al . ). This variation could be species dependent, and the optimal dietary protein intake for H. midae largely considered to be 36% of the total nutrient intake (Robertson‐Andersson et al .…”