Abstract:
The longfin yellowtail Seriola rivoliana is an emerging species for aquaculture diversification worldwide and production relies on fertilized eggs from captive broodstock. Temperature is the main factor that influences the developmental process and success during fish ontogeny. However, the effects of temperature on the utilization of the main biochemical reserves and bioenergetics are scarcely investigated in fish, whereas protein, lipid and carbohydrate metabolism have critical roles in maintaining cellular energy homeostasis. In this context, we aimed to evaluate metabolic fuels (protein, lipids, triacylglicerides, carbohydrates), adenylic nucleotides and derivates (ATP, ADP, AMP, IMP), and the adenylate energy charge (AEC) during embryogenesis and in hatched larvae in S. rivoliana at different temperatures. For this purpose, fertilized eggs were incubated at six constant (20, 22, 24, 26, 28 and 30 °C) and two oscillating (21⇄29 °C) temperatures. Biochemical analyses were made at blastula, optic vesicles, neurula, prehatch and hatch periods. Results indicated that the developmental period had a major influence on the biochemical composition at any temperature regime tested during the incubation. Protein content decreased only at hatching mainly due to the loss of the chorion, total lipids tended to increase at the neurula period and variations in carbohydrates depended on the particular spawn analyzed. Triacylglicerides were a critical egg fuel during hatching. The high AEC during embryogenesis and even in hatched larvae suggested an optimal energy balance regulation. The lack of critical biochemical changes from different temperature regimes during embryo development confirmed that this species exhibits a high adaptive capacity in response to constant and fluctuating temperatures. However, the timing of hatching was the most critical period of development, where biochemical components and energy utilization significantly changed. The oscillating temperatures tested may have physiological advantages without detrimental energetic effects that will require further research on larval quality after hatching.
摘要:
长鳍黄尾Seriolarivoliana是全球水产养殖多样化的新兴物种,生产依赖于圈养亲鱼的受精卵。温度是影响鱼类个体发育过程和成功的主要因素。然而,在鱼类中很少研究温度对主要生化储备和生物能利用的影响,而蛋白质,脂质和碳水化合物代谢在维持细胞能量稳态方面具有关键作用。在这种情况下,我们旨在评估代谢燃料(蛋白质,脂质,三酰甘油,碳水化合物),腺苷酸核苷酸和衍生物(ATP,ADP,AMP,IMP),以及在不同温度下,拟南芥胚胎发育过程中和孵化幼虫中的腺苷酸能量电荷(AEC)。为此,受精卵在六个恒定温度(20、22、24、26、28和30°C)和两个振荡温度(21^29°C)下孵育。在囊胚处进行了生化分析,视神经囊泡,神经,早熟和孵化期。结果表明,在孵育过程中测试的任何温度条件下,发育期对生化组成都有重大影响。蛋白质含量仅在孵化时下降,主要是由于绒毛膜的损失,总脂质在神经周期趋于增加,碳水化合物的变化取决于分析的特定菌种。三酰甘油是孵化过程中的关键卵燃料。胚胎发生期间甚至在孵化幼虫中的高AEC表明了最佳的能量平衡调节。胚胎发育过程中缺乏来自不同温度状态的关键生化变化,这证实了该物种对恒定和波动的温度具有很高的适应能力。然而,孵化的时机是最关键的发育时期,其中生化成分和能量利用发生了显著变化。测试的振荡温度可能具有生理优势,而不会产生有害的能量影响,这需要对孵化后的幼虫质量进行进一步研究。