七彩神仙鱼繁殖间期与繁殖期体表黏液的部分组分分析

为了探究七彩神仙鱼体表黏液在繁殖周期中组分的变化规律,测定七彩神仙鱼体表黏液中皮质醇、免疫球蛋白M、总蛋白、乳酸和葡萄糖的含量变化。结果表明,七彩神仙鱼体表黏液中皮质醇、免疫球蛋白M、总蛋白、乳酸和葡萄糖的含量均受亲鱼性别和繁殖时期显著影响,且繁殖时期与性别之间存在显著交互作用。在幼鱼平游期,5种组分含量在雌雄亲鱼之间存在显著差异。七彩神仙鱼开始"喂奶"后其体表黏液成分发生显著变化,尤其是雄鱼会分泌更多的营养与免疫组分来满足幼鱼需求。

Epidermal mucus components analysis of discus fish(Symphysodon haraldi) during breeding period and interval-breeding period

To investigate the components change in epidermal mucus of discus fish (Symphysodon haraldi) during the breeding period, we measured the contents of cortisol, IgM, total protein, lactic acid and glucose in the epidermal mucus during the whole breeding cycle, and examined the hydrolyzed amino acid profiles in breeding period and interval-breeding period. The results showed that the contents of cortisol, IgM, total protein, lactic acid and glucose in the epidermal mucus of S. haraldi were significantly influenced by fish gender, sampling period and their interaction (P<0.05). During the free-swimming period, significant differences in the concentrations of the five components between male fish and female fish were observed (P<0.05). No significant difference in the water content of epidermal mucus between male fish and female fish (P>0.05). As for the profiles of hydrolyzed amino acids, Glu, Asp, Leu and Lys showed the highest contents in the epidermal mucus. The contents of hydrolyzed amino acids in the epidermal mucus of female fish were significantly lower than those of male fish during breeding period and interval-reproductive period (P<0.05). The concentrations of hydrolyzed amino acids in male fish rather than in female fish were significantly increased after they entered the breeding period (P<0.05). In conclusion, significant changes in the epidermal mucus composition of the parental discus fish would occur when the larvae start to suckle in the free-swimming period, and the epidermal mucus of parental fish would secrete more nutrient and immune components to feed the larvae. Male discus fish could provide more nutrient and immune components than the female fish for larvae from epidermal mucus during the free-swimming period.