闽东海域银鲳亲鱼性腺发育后期脂类及脂肪酸蓄积特点

脂肪和脂肪酸是海水鱼类早期生长发育的重要结构物质和能量来源。亲鱼的脂肪和脂肪酸储备影响其繁殖性能和早期仔鱼的发育。为了获知银鲳亲鱼性腺发育后期脂类及脂肪酸蓄积特点,本研究采用氯仿甲醇法及气相色谱法定量检测了繁殖季节闽东海域野生银鲳亲鱼不同组织的总脂肪及脂肪酸含量。结果表明:亲鱼卵巢、精巢、肝脏和肌肉的总脂肪含量差异显著。卵巢、精巢、肝脏和肌肉的总脂含量分别为:35.76%,15.11%,22.07%和22.14%(占组织干重)。极性脂肪占总脂肪的比例在精巢中最高,其次为肝脏和卵巢,在肌肉中最低。性腺从Ⅳ期发育到Ⅴ期,雌鱼卵巢总脂肪和中性脂肪含量显著增加,雄鱼肌肉极性脂肪含量显著降低。中性脂肪中卵巢的20∶5n-3(EPA,2.25~3.87 mg/g)、22∶6n-3(DHA,6.71~13.03mg/g)和高不饱和脂肪酸(HUFAs,17.20~29.64 mg/g)含量最高,极性脂肪中精巢的EPA(0.38~0.27 mg/g)和DHA(3.12~3.59 mg/g)含量最高。性腺中n-3/n-6比值显著高于肝脏和肌肉中。随着卵巢发育,DHA等必需脂肪酸在雌鱼不同组织及同一组织不同脂肪类别之间存在转移现象。研究表明,银鲳亲鱼各组织的总脂肪含量、总脂肪组成及脂肪酸绝对含量(mg/g干物质)具有组织特异性,随着性腺发育,必需脂肪酸总体上表现为由肌肉和肝脏向性腺中转移,且性腺中脂肪酸的变化主要发生在中性脂肪中。

Characteristics of lipid and fatty acid accumulation in wild-caught broodstocks of Pampus argenteus from Mindong Seazone

Lipid and fatty acids are among the most vital factors that provide marine fish with structural components and energy resources.The fatty acid reserves of broodstocks profoundly affect the fecundity of spawners as well as the quality of the newly hatched larvae.In order to state the characteristics of lipid and fatty acid accumulation in wild-caught broodstocks of Pampus argenteus,the lipid and fatty acid content in different tissues of wild broodstocks of silver pomfret,Pampus argenteus from Mindong Seazone during the reproductive season were quantitatively investigated with the methods of chloroform-methanol and gas chromatography.The results indicated that there were significant differences in lipid content among gonad,liver and muscle.Mean total lipid levels(% in dry weight)in ovary,testis,liver and muscle were 35.76%,15.11%,22.07% and 22.14%,respectively.Testis displayed the highest proportion of polar lipid/total lipid,while muscle displayed the lowest proportion of polar lipid/total lipid.During the reproductive season,the total lipids and neutral lipid contents in ovary increased significantly with the development of the ovary,while the polar lipid content in muscle decreased significantly with the development of the testis.The contents of 20:5n-3(EPA,2.25-3.87 mg/g),22:6n-3(DHA,6.71-13.03 mg/g)and highly unsaturated fatty acids(HUFAs,17.20-29.64 mg/g)in neutral lipid of ovary were the highest.The contents of EPA(0.38-0.27 mg/g)and DHA(3.12-3.59 mg/g)in polar lipid of testis were the highest.The n-3/n-6 ratio in gonad was significantly higher than those in liver and muscle.The essential fatty acids such as DHA were transferred among the tissues and between different lipid classes of the same tissue.It is therefore suggested that significant differences in total lipid content,total lipid classes and fatty acid contents(mg/g dry mass)were displayed not only among the tissues,but also between different lipid classes of the same tissue.The essential fatty acids were preferentially transferred from neutral lipid in muscle and liver to neutral lipid in ovary with the maturation of ovary.