What question did this study set out to answer?

To evaluate the potential of Ulva australis and Sargassum horneri as dietary replacements for Undaria pinnatifida in abalone aquaculture.

February 11, 2026

Evaluation of Ulva australis, singly or combined with Sargassum horneri, as a replacement for Undaria pinnatifida in abalone (Haliotis discus hannai): effects on growth, insulin signaling pathway, digestion, immune function, and meat sensory characteristics

Key Points

To evaluate the potential of Ulva australis and Sargassum horneri as dietary replacements for Undaria pinnatifida in abalone aquaculture.
Abalone (Haliotis discus hannai) were fed three diets for 6 months: Con (U. pinnatifida), Diet 1 (100% U. australis), and Diet 2 (1:1 U. australis and S. horneri).
Growth performance, insulin signaling pathway gene expression, digestion, immune function, and meat sensory characteristics were assessed.
Statistical analyses were conducted to compare effects among different dietary treatments.
Diet 2 improved growth performance most significantly compared to other diets (p < 0.05).
Insulin signaling pathway genes (AIP2, IR, PI3K, AKT, mTOR, S6K) were upregulated in abalone fed Diet 2 (p < 0.05).
Concentration of α-amylase and intestinal villi height were highest in Diet 2 (p < 0.05).
Immune gene expression (NF-κB and TNF-α) was elevated with Diet 2 (p < 0.05).
Collagen content and muscle hardness were also superior in Diet 2 (p < 0.05).

Abstract

The growth of abalone aquaculture necessitates a consistent supply of seaweed resources and biofouling macroalgae have been identified as a potential supplementary component in aquafeed formulation. In this study, the effects of replacing Undaria pinnatifida with Ulva australis and Sargassum horneri in the diet of abalone ( Haliotis discus hannai ) were evaluated. The dietary treatments—Con (containing U. pinnatifida ), Diet 1 (100% replacement with U. australis ), and Diet 2 (100% replacement with 1:1 mixture of U. australis and S. horneri )—were fed to the abalone (0.43 ± 0.09 g, 15.37 mm) for 6 months. Growth performance was statistically the highest in Diet 2, followed by Diet 1 and Con groups ( p < 0.05 ). The expression of insulin signaling pathway genes (AIP2, IR, PI3K, AKT, mTOR, and S6K) and muscle structural genes (MHC and Col1α) were upregulated in Diet 2 compared to the Con-fed abalone ( p < 0.05 ). Likewise, the concentration of α-amylase, intestinal villi height and expression of immune genes (NF-κB and TNF-α) was the highest in Diet 2 ( p < 0.05 ). Collagen content and hardness in the muscle was the highest in the Diet-2 fed-abalone ( p < 0.05). Sensory evaluation revealed comparable taste profile and is irrespective of the diets given. These findings illustrate that the biofouling macroalgae can effectively utilized as U. pinnatifida replacement in the feed formulation for abalone, contributing to improved growth, stronger immunity and consistent meat sensory attributes.

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Cite This Study

Lee et al. (Mon,) studied this question.

synapsesocial.com/papers/698be001058ab1890a13bb10 https://doi.org/https://doi.org/10.1007/s10811-026-03788-x

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