Metabolomics Adaptation of Juvenile Pacific Abalone Haliotis discus hannai to Heat Stress

Abstract

Temperature fluctuation is a key abiotic factor for the growth and survival of Pacific abalone Haliotis discus hannai, particularly during climate change. However, the physiological mechanism underlying the abalones' response to heat stress remains unknown. We sought to understand the metabolic adaptation mechanism of Pacific abalone to heat stress for further analyzing its heat tolerance capacity. For two groups experienced different acclimate temperature (10 °C and 30 °C for 62 days), the Pacific abalone juveniles displayed significantly different survival rates under 31 °C acute heat treatment. A total of 1815 and 1314 differential metabolites were identified from the 10 °C and 30 °C acclimate groups respectively, by comparing mass spectrometry data of the samples before and after heat stimulation. Heat stress led to mitochondrial failure, resulting in incomplete oxidative metabolism of amino acids and fatty acids in the mitochondria, and massive accumulation of unstable metabolic intermediates in cells. The 10 °C acclimated group accumulated more harmful substances after heat stimulation, provoking further stress responses and pathophysiological processes. In comparison, the 30 °C acclimated group showed stronger regulation capacity to produce beneficial substances for metabolic homeostasis. The findings provided insight into the heat response of marine animals, especially concerning mitochondrial metabolism. Global warming will trigger more extreme weather events that can potentially be deleterious to marine animals, especially the ones distributed in the intertidal and neritic zones 1,2. Organisms inhabiting this range face higher water temperature elevations and more environmental fluctuations during the summer season. Aquaculture animals, which are subjected to fluctuations in natural conditions, are more vulnerable to these physical and chemical stimulations as they are usually stocked intensively at high density and rely on water influx from coastal areas 3. Even a slight change in the climate may cause enormous economic losses in mariculture. The analysis of thermal stress on aquaculture animals has thus gained more research interests 4-7. Pacific abalone Haliotis discus hannai, a cold water gastropod, is the predominantly farmed abalone species in many Asian countries 8. It is naturally distributed in cold water, implying that high temperatures would limit its southern expansion along the Asian coast. In recent years, the dominant aquaculture strategy in China is transferring juvenile abalones to warmer south China during the winter, thereby accelerating the animal's growth rate. In the meantime, the traditional genetic selection based on growth traits may contribute to a decreased heat stress tolerance of the organism. Consequently, the massive mortality in summer months has become a challenge that has led to an enormous economic loss in abalone and the entire molluscs industry in recent years 9. While some overwintering abalones were transferred back to the northern region during spring, some were c...

Temperature adaptations of the thermophilic snail Echinolittorina malaccana: insights from metabolomic analysis

“…The fact that temperature has pervasive effects on biological structures and rates of physiological activity underlies the importance of elucidating the fundamental mechanistic determinants of thermal optima and thermal limits, which play crucial roles in determining species distribution patterns and sensitivities to anthropogenic climate change (Somero, 2012;Somero et al, 2017). Although much progress has been made in clarifying the bases of biochemical and physiological adaptation (Angilletta, 2009;Cossins and Bowler, 1987;Somero et al, 2017), particularly at the level of individual proteins (Dong et al, 2018;Liao et al, 2017;Somero, 2004), metabolic pathways (Noda-Garcia et al, 2018;Götze et al, 2020;Xu et al, 2020), and membrane structure and function (e.g. homeoviscous and homeophasic adaption; Hazel, 1995;Logue et al, 2000;Somero et al, 2017), there remain many unanswered questions about the mechanisms that set the thermal limits for life.…”

Dynamics and Microevolution of Vibrio parahaemolyticus Populations in Shellfish Farms

“…Thus, the transport of live aquatic animals deliberately delivered to distant farms in large quantities could have facilitated the transmission of bacteria among different regions or countries. For our cases, the epidemiological investigation showed that a large number of abalone, sea cucumber, and other aquatic animals were transported from Liaoning and Shandong to Fujian province from later October to early November, as high temperatures in South China would promote the growth of aquatic animals and shorten their life cycle ( 22 ). Such large-scale movement of live aquatic animals from north to south (or the reverse direction) would have profound effects on the mixing of V. parahaemolyticus populations.…”

Metabolite profiling of abalone (Haliotis iris) energy metabolism: a Chatham Islands case study

“…Understanding how the environment influences the metabolism and growth of abalone in fished populations is central to effective fisheries management (Naylor et al, 2006 ). Metabolic studies have previously been performed on juvenile or adult H. midae (Venter et al, 2019 ), H. iris (Grandiosa et al, 2018 ), H. fulgens (Tripp-Valdez et al, 2019 ) and H. discus hannai (Xu et al, 2020 ), yet metabolomics characterisation of a population to guide stock and fisheries management or translocation practises remains an untouched subject.

Fig.

…”