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Litopenaeus vannamei is an important aquaculture species in China. Selective breeding is an effective means to improve the economic benefits of aquatic animals. In terms of the energy budget, water temperature is the key factor affecting the metabolism of aquatic invertebrates at different stages. It affects their survival and overall growth and may become a fatal environmental driver. Therefore, in recent years, the impact of temperature on the energy budget of important economic aquatic animals has attracted extensive attention. Taking L. vannamei as an example, the energy budget under constant and variable temperature conditions was studied. In order to further develop the breeding of L. vannamei and clarify its energy distribution mode under different temperature conditions, this study used three families of L. vannamei (N310010, N310004, and N310011) as materials and measured their individual energy budget at the temperature of 20 ℃ to 35 ℃ during 40 days. The physiological indexes such as feeding, oxygen consumption, ammonia excretion, and fecal excretion rates were measured every ten days. The individual energy budget of L. vannamei families with different specifications (S1, S2, S3, and S4) was analyzed. The results based on the range temperature of 20 ℃ to 35 ℃ showed the total specific growth rate of 9.79% for the N31004 family, which was significantly higher than that of the other two families (P < 0.05). In the S1~S2 period, the specific growth rate of the N31004 family was significantly higher than that of other families (P < 0.05), in which the highest rate was 27.76%. In the S2~S3 period, there was no significant difference between the N31004 and N310011 families, while the N31004 family growth rate of 5.79% was significantly higher than that of the other two families, while the lowest was 3.07% observed in the N310011 family. Moreover, the highest feeding rate [0.026 g/(g·d)] was found in S1, and the lowest [0.005 g/(g·d)] was observed in S4. Overall, the feeding rate of L. vannamei with different specifications and families was significantly different (P < 0.05). The feeding rate of the N31004 family was higher than that of the other two families at 20 ℃ in the S1 period, whereas the feeding rate of N310004 family was significantly higher than that of the other two families in the S2, S3, and S4 periods. Furthermore, in N310011, the oxygen consumption rate was significantly higher than in the other two families at 25 ℃ to 35 ℃ in the S1 period and 35 ℃ in the S2 period. There was no significant difference between the oxygen consumption rate of the other two families (N310010 and N31004) under these conditions. The N310010 oxygen consumption rate was significantly higher than the other two families at 30 ℃ to 35 ℃ in the S3 period and 20 ℃ to 35 ℃ in the S4 period. In the S1 to S3 periods, the N31004 oxygen consumption rate was significantly lower than the other two families at all temperatures. In the S4 period, there was no significant difference among the three families at 30 ℃ to 35 ℃. Overall, the ammonia excretion rate of the N31004 family was significantly lower than the other two families. Finally, the maximum feeding energy of the N31004 family was 1 510.62 J/(g·d) at 35 ℃ and the minimum was 812.47 J/(g·d) at 20 ℃, which were significantly higher than those of the other two families at all temperatures. N310010 showed the highest respiratory energy at 35 ℃ [1 061.15 J/(g·d)] and the lowest at 20 ℃ [566.18 J/(g·d)], which was significantly higher than the other two families. The excretion energy of N310010 family was significantly higher than that of the other two families at each temperature. The growth energy of the N31004 family was the highest at 30 ℃ [298.45 J/(g·d)] and the lowest at 20 ℃ [163.61 J/(g·d)]. The defecation energy of the N310010 family was significantly lower than that of the other two families. Compared with the other two families, N31004 had more energy for growth, although the respiratory excretion energy was relatively low. It is of great significance for the L. vannamei breeding to deeply understand the effects of physical and chemical environmental factors such as temperature on the growth, development, and energy budget of different L. vannamei families from a physiological and ecological perspective, clarifying the L. vannamei energy distribution mode under different temperature conditions. Currently, there are no reports on the energy basis and temperature effect of the growth rate of diverse L. vannamei families. Therefore, by establishing energy distribution models, this study explores the impact of temperature on the energy budget and distribution of L. vannamei and provides theoretical and experimental support for healthy culture and breeding of improved L. vannamei varieties. |
