Effects of temperature and female-male mating ratios on energy metabolism of Macrobrachium rosenbergii

Abstract

[Objective] This article aimed to explore the effects of temperature and female-male mating ratio on energy metabolism and growth of Macrobrachium rosenbergii in order to provide scientific basis for further analysis and solution of the slow growth of M. rosenbergii.

[Method] According to the energy budget equation [the consumption energy (Ce) = growth energy (Ge)+defecation energy (Fe)+excretion energy (Ue)+molting energy (Ee)+respiratory energy (Re)] and the Kaiser method, the energy values of each part was calculated. the effects of four temperatures (20, 22, 26, 30 °C) and three male-female ratios (1:1, 1:2, 1:3) on energy metabolism and growth of M. rosenbergii were analyzed.

[Result] The absolute level of Ce of female and male M. rosenbergii increased with the increase of temperature, and was significantly different between groups of female M. rosenbergii, as well as groups of non-adjacent temperature levels of male M. rosenbergii ( P<0.05, the same below). The absolute level of Ge of the male was significantly higher than that of other groups at 26 °C, and that of the female was significantly higher than that of 20 and 22 °C. The female and male did not molt at 20 °C, and the absolute levels of Ee increased with the increase of temperature from 22 to 30 °C, reaching the maximum at 30 °C (female 1371±272 J/g, and male 1035±598 J/g). The specific growth rates (SGR) of female and male M. rosenbergii were significantly higher at 26 °C than that of the other three groups; the absolute level of Re of female M. rosenbergii was significantly higher in higher temperature groups (26 and 30 °C) than that in lower temperature groups (20 and 22 °C). In the test of sexually mature female and male shrimp raised separately, the absolute levels of Ce, Ge and SGRs were decreasing by the increasing population of male shrimp, that of one male shrimp in the sink significantly higher than that of two and three male shrimps in the sink; and the absolute level of Re of mature male shrimps increased significantly with the increase of population. In the test of different male-female mating ratios of M. rosenbergii, and there was a negative growth at the female-male ratio of 1:3; the SGR of the female-male ratio at 1:1 level was significantly higher than that at 1:2 and 1:3 levels, and the absolute level of Ue of the female-male ratios at 1:1 level was significantly lower than that at 1:2 and 1:3 levels, and its share of Ce also increased by the increasing population of male shrimp.

[Conclusions] Relative high temperature is more suitable for the growth and development of M. rosenbergii, and 26 °C is the most suitable temperature, in which the metabolism of M. rosenbergii is more vigorous. It is concluded that the energy accumulation during the growth of sexually mature M. rosenbergii may be affected by its biological behavior such as fighting, occupying area and mating, and the increase of male shrimp proportion may aggravate the effect.

Abstract

摘要：【目的】探索水温和雌雄配比对罗氏沼虾 ( Macrobrachium rosenbergii)能量代谢和生长的影响,为进一步分 析与解决罗氏沼虾生长缓慢的问题提供科学依据。 【方法】根据能量收支方程[摄食能 (Ce)=生长能 (Ge)+排粪能 (Fe)+排泄能 (Ue)+蜕壳能 (Ee)+呼吸能 (Re)]及凯式定氮法, 分别计算罗氏沼虾各部分的代谢能值, 分析4种水温 (20、22、26和30 °C)及3种雌雄配比 (1: 1、1:2和1:3)对罗氏沼虾能量代谢和生长的影响。 【结果】雌、雄罗氏沼虾的绝 对摄食能均随水温上升而升高, 其中雌虾在各水温处理组间差异显著 ( P<0.05, 下同), 雄虾则表现为非相邻水温处理 组间差异显著;雄虾在26 °C下的绝对生长能显著高于其他3个水温处理组, 雌虾在26 °C下的绝对生长能显著高于20 和22 °C水温处理组;雌、雄罗氏沼虾在20 °C下均未蜕壳, 在22∼30 °C下其绝对蜕壳能随水温上升而升高, 在30 °C时 达最大值 (雌虾1371±272 J/g, 雄虾1035±598 J/g);雌、雄罗氏沼虾的特定生长率在26 °C下显著高于其他3个水温处理 组;罗氏沼虾的绝对呼吸能表现为高温处理组 (26和30 °C)高于低温处理组 (20和22 °C)。单性饲养下, 性成熟雄虾 的绝对摄食能、绝对生长能和特定生长率随数量上升而降低, 且每个水槽放养1尾雄虾显著高于每个水槽放养2~3尾 雄虾;性成熟雄虾绝对呼吸能则随数量上升而显著升高。不同雌雄配比下, 性成熟罗氏沼虾的绝对生长能随雄虾数 量上升而显著降低, 雌雄配比1:1的特定生长率显著高于雌雄配比1:2和1:3;雌雄配比1:1的绝对排泄能显著低于雌 雄配比1:2和1:3, 其占摄食能的百分比随雄虾数量上升而上升。 【结论】高温更适合罗氏沼虾的生长发育, 且以26 °C 最适宜, 在此水温条件下罗氏沼虾新陈代谢更旺盛。在性成熟罗氏沼虾生长过程中, 其能量积累可能受打斗、占区和 交配等生物学行为影响, 且相同密度下雄虾比例增加有可能加剧影响。