美洲鲥当年鱼种池塘大棚越冬养殖试验

Overwintering culture experiment of young fish Alosa sapidissima in greenhouse ponds

摘要:

于2017—2019年采用在池塘上方搭建简易保温大棚的方式开展了美洲鲥当年鱼种越冬养殖试验,研究探讨了越冬养殖相关的技术参数。结果显示:搭建保温大棚后,冬季池塘水温可保持在10 ℃以上,在美洲鲥当年鱼种(0⁺龄鱼种,平均体长12.45~16.65 cm,平均体质量27.29~66.41 g)放养密度为1 518~2 970尾/亩(15亩=1 hm²,下同)和81.04~100.78 kg/亩的条件下,在越冬前中期(12月至次年3月中旬),日投饲量在0.8~1.6 kg/亩,越冬后期(次年3月中旬至4月上中旬),日投饲量也由2.0 kg/亩左右迅速增加到4.0~5.0 kg/亩。经过125~130 d的越冬养殖,鱼种平均体长达17.48~21.19 cm,增长28.04%~40.40%,平均体质量77.57~137.96 g/尾,增加了106.53%~184.24%,鱼种的体长和体质量特定生长率分别为(0.193~0.261)%/d和(0.585~0.804)%/d,日均增长量和日增重分别为0.036~0.039 cm/d和0.387~0.572 g/d；收获时美洲鲥鱼的肥满度为1.42~1.43 g/cm³,养殖成活率为89.29%~94.81%,饲料系数为1.50~1.65,亩产量为198.50~205.68 kg。试验结果表明,在江浙地区,养殖池塘上方搭建保温大棚后,冬季池塘水温(10~20 ℃)在美洲鲥当年鱼种的适宜水温范围,能获得较理想的越冬养殖效果。

Abstract:

In order to explore the overwinter rearing technology of 0⁺ age young fish Alosa sapidissima,this study investigated the growth characteristics of young fish A.sapidissima under greenhouse pond condition from 2017 to 2019.The results showed that the water temperature could be kept above 10 ℃ under the greenhouse pond condition and the feeding amount was 12~24 kg/hm² at the early and middle of winter(December to the middle of the following March),and the feeding amount increased from about 30 kg/hm² to 60~75 kg/hm² at the end of winter(mid-March to mid-April of the following year)at an initial stocking density of 2.28×10⁴~4.46×10⁴ ind/hm² and 1 215.60~1 511.7 kg/hm².After 125~130 d of rearing,the average body length of experimental fishes increased from initial 12.45~16.65 cm to final 17.48~21.19 cm with 28.04%~40.40% of gain rate,the average body weight increased from initial 27.29~66.41 kg to final 77.57~137.96 g with 106.53%~184.24% of gain rate.The specific growth rate of average body length and body weight of experimental fishes was (0.193~0.261)%/d and(0.585~0.804)%/d,respectively.The daily body length and weight gain was 0.036~0.039 cm/d and 0.387~0.572 g/d,respectively.At the end of the experiment,the condition factor(CF),survival rate, feed conversion ratio(FCR)and yield of fishes were 1.42~1.43 g/cm³,89.29%~94.81%,1.50~1.65 and 2 977.50~3 085.2 kg/hm²,respectively.In conclusion,young fish A.sapidissima exhibited good growth performance under greenhouse pond condition and 10~20 ℃ could be optimal for the growth of 0⁺ age young fish A.sapidissima in winter at Jiangsu and Zhejiang area.