循环水养殖系统中养殖密度对松江鲈生长的影响

Effects of stocking density on growth of Trachidermus fasciatus in the recirculating aquaculture system

摘要:

为研究配合饲料条件下循环水养殖系统(RAS)中养殖密度对松江鲈生长的影响,选取体长为(2.97±0.12)cm、体质量为(0.26±0.03)g的松江鲈,分别按40尾/m²(A组)、80尾/m²(B组)和120尾/m²(C组)共3个养殖密度,在RAS中进行了为期240 d的养殖试验。试验结果显示:A组鱼的终末体质量、终末体长、体质量日增长量、存活率等均显著高于其他两组,A组鱼的体长日增长量显著高于C组(P＜0.05)；不同密度组间鱼体肥满度无显著性差异(P＞0.05)。试验组单位面积产量由高到低依次为:C组(2.83 kg/m²)、B组(2.51 kg/m²)、A组(1.72 kg/m²)。试验组鱼体质量与体长均呈幂函数相关(m=aL^b,a=0.007 6～0.008 9,b=3.123 6～3.209 4),体长、体质量生长均以三次函数拟合较好。各组间的鱼体长、体质量变异系数均差异显著(P＜0.05),其中B组最小。试验表明:在配合饲料条件下,随着养殖密度的提高,RAS养殖的松江鲈生长性能逐渐降低,其合理的养殖密度为40～80尾/m²。在本试验条件下,建议在养殖早期采用高密度养殖模式,同时加强养殖期间对水温的控制和管理。

Abstract:

To investigate the influence of stocking density on the growth of Trachidermus fasciatus in the recirculating aquaculture system(RAS) under the condition of formula feed,T. fasciatus with initial body length of (2.97±0.12)cm and initial body mass of (0.26±0.03)g were cultured in RAS at stocking densities of 40 ind/m²(group A),80 ind/m²(group B) and 120 ind/m²(group C).The test period was 240 days.The results showed that the highest body weight,body length,daily gain and survival rate was observed in group A,and the daily growth of body length in group A was significantly higher than group C(P<0.05).There was no significant difference in coefficient of fatness among groups(P>0.05).Output per unit area of 3 groups:group A(1.72 kg/m²)2)2).The body mass was shown to be correlated with body length using a power function m=aL^b(a=0.007 6-0.008 9,b=3.123 6-3.209 4),and the relationship between body length or body weight and culture days was well described by cubic function.There was significant difference in the coefficient of variation of body length and body mass among the three groups(P<0.05),and group B was the smallest.The findings indicated that T. fasciatus had a decrease in growth performance with the increase of stocking density,and the optimal stocking density was 40-80 ind/m² under the condition of formula feed.It is suggested that high-density culture pattern should be adopted in the early stage of culturing,and the control and management of water temperature should be strengthened during culturing in these experimental conditions.