稀有鮈鲫饲料营养及饲养技术的实验研究

Nutrition Standardization for Rare Minnow (Gobiocypris rarus):Artificial Diets and its Suitable Rearing Strategies

目的探索稀有鮈鲫应用型配合饲料及相应的养殖技术,促进实验稀有鮈鲫的营养学标准化。方法在营养学需求的研究基础上,探索并验证适合稀有鮈鲫日常养殖的应用型配合饲料。通过生长实验和繁殖实验,筛选得到适宜的饲料配方;研究了温度、投喂频率、饲养密度等饲养策略对生长、性腺发育的影响。结果 25%~40%蛋白水平的配合饲料均可满足幼鱼快速生长需求,其中30%蛋白、6%脂肪、总能为12.5 kJ/g的投喂效果生长最好,同时,繁殖性能较高,可达到对照组的69.4%;亲鱼的产卵间隔随饲料蛋白水平的降低而延长;在18~24℃范围内,温度越高,生长越快,当温度超过28℃时,体质量反而有所下降;不同投喂频率下,最大生长均出现在24℃时;特定生长率随养殖密度升高呈明显下降的趋势,养殖密度为0.8尾/L时饲料利用率最高,1.6尾/缸组稍降低,但无显著差异。结论 30%蛋白、6%脂肪、总能为12.5 k J/g的配合饲料可满足稀有鮈鲫幼鱼的快速生长,且能使亲鱼能保持规律性繁殖,满足实验稀有鮈鲫传代和生产需要;过高或过低的温度对生长不利,投喂频率的增加不一定能促进生长和饲料利用;稀有鮈鲫幼鱼适宜的养殖温度为24~26℃,每天投喂2次;养殖密度对生长和性腺发育均有很大影响,适宜的养殖密度应不超过1.6尾/L。

Objective To explore applicable artificial diets and its suitable rearing strategies for this laboratory fish （Gobiocypris rarus） and improve its nutrition standardization.Method Artificial diets were designed based on nutrition requirement and tested in growth and reproduction experiments,and effects of different rearing strategies such as temperature,feeding frequency and stocking density on the growth and reproduction were revealed fed with suitable artificial diets.Result Diets with 25% ~ 40% crude protein could meet the requirement for fast growth of rare minnow,especially the diet with 30% crude protein,6% crude lipid and 12.5 k J/g gross energy,could also promote the reproductive performance,and the success rate of reproduction could achieve 69.4% compared to those fed with red worms （Chironomus larva）.The spawning interval decreased with increasing dietary protein.The growth rate increased with increasing water temperature in 24 ~ 28℃,but descended with over high temperature.The optimal culture temperature was 24℃ when feeding 1 ~ 3 meals a day.The growth rate decreased with increased stocking density,the feed efficiency was higher in 0.8 fish/L and the optimal stocking density was 1.6 fish/L.Conclusion The artificial diets with 30% crude protein,6% crude lipid and 12.5 k J/g gross energy could meet the requirement for fast growth of rare minnow,also,the parent fish could reproduce regularly.Too high or too low temperature could affect the growth of rare minnow adversely.High feeding frequency could not always promote the growth and feed conversion rate.The optimal culture temperature for rare minnow was 24℃ to 26℃,and feeding frequency was 2 meals per day.Stocking density obviously affected the growth and gonad development of rare minnow,the optimal density in recirculating aquaculture system should be controlled at 1.6 fish/L or lower.