关键词: 牙鲆, 生长参数, 体型参数, 抗病性, 尾水, 氮, 磷

Abstract: 【Objective】Improve the germplasm of cultivated Paralichthys olivaceus in Tianjin to promote the economic and ecological benefits of fisheries in the region.【Methods】The Paralichthys olivaceus “Pingyou No. 2” was trial bred from September 2018 to May 2019. Using the character comparison approach,the growth,body shape,disease resistance,and nitrogen and phosphorus production per unit weight gain of “Pingyou No. 2” were examined.【Results】The absolute weight gain rate of “Pingyou No. 2” was 19.41% higher and the absolute growth rate was 16.67% higher than that of common Paralichthys olivaceus. In comparison with common Paralichthys olivaceus,the average coefficient of fatness of “Pingyou No. 2” was 22.87% lower and the total length/body length was 0.89% lower. There was no difference in other body parameters. “Pingyou No. 2” had a lower coefficient of variation for weight,total length,body length,head length,and body height than the common Paralichthys olivaceus by 8.07%,16.03%,16.07%,30.31%,and 27.88%,respectively. When compared to common Paralichthys olivaceus,the mortality for “Pingyou No. 2” ascites disease and lymphatic cyst disease were 73.95% and 67.14% lower. During the experiment,the final survival rate of“Pingyou No. 2” was 31.07% higher than that of common Paralichthys olivaceus. For every kilogram of body weight gained,the tail water concentrations of newly added ammonium nitrogen,total nitrogen,soluble phosphate,and total phosphorus in “Pingyou No. 2” were 48.56%,35.37%,29.68% and 37.36% lower than common Paralichthys olivaceus.【Conclusion】In terms of growth,body shape variation,disease resistance,nitrogen and phosphorus output per unit weight gain,“Pingyou No. 2” outperformed regular Paralichthys olivaceus,suitable for promoting in Tianjin.

Key words: Paralichthys olivaceus, Growth parameters, Dody shape parameters, Disease resistance, Tail water, Nitrogen, Phosphorus