吕泗渔场主要渔获物春夏秋三季脂肪酸组成及食性分析

Fatty Acid Composition and Feeding Habits Analysis of the Main Catches from Lüsi Fishing Ground during Spring,Summer and Autumn

为探究吕泗渔场主要渔获物营养价值、食性及季节变化,于2018年5、8和10月渔业资源调查采集渔获物,测定其脂肪酸组成,采用脂肪酸标记法进行食性分析。结果显示,8种主要渔获物多不饱和脂肪酸/饱和脂肪酸(PUFA/SFA)为0.88~1.79,n-3/n-6为2.56~3.18,C16:1n7和Σ15+Σ17夏季显著增加(P<0.05),C20:5n3+C22:6n3(EPA+DHA)、PUFA/SFA、n-3/n-6、C20:4n6、C22:6n3和Σ22+Σ24秋季显著增加(P<0.05),C20:1+C22:1秋季显著减少(P<0.05)。各渔获物营养价值较高且秋季显著高于春、夏季,其中,棘头梅童鱼(Collichthyslucidus)和小黄鱼(Larimichthyspolyactis)营养价值最优。DHA/EPA和聚类分析将渔获物分为3组:哈氏仿对虾(Parapenaeopsis hardwickii)、周氏新对虾(Metapenaeus joyneri)和日本蟳(Charybdis japonica);凤鲚(Coilia mystus)、皮氏叫姑鱼(Johnius belangerii)、棘头梅童鱼和小黄鱼;银鲳(Pampusargenteus)。哈氏仿对虾、周氏新对虾、日本蟳植食性和底栖生物食性明显,凤鲚和小黄鱼浮游动物食性明显,银鲳植食性和浮游动物食性明显,皮氏叫姑鱼和棘头梅童鱼食性无明显偏好。夏季,硅藻和细菌食源显著增加;秋季,底栖生物、甲藻和陆生植物食源显著增加,浮游动物食性显著减少。

In order to explore the nutritional value,feeding habits and seasonal changes in the main catches from Lüsi fishing ground,we measured fatty acid composition of the main catches collected through a fishery resources survey in May 2018,August 2018,and October 2018.We analyzed feeding habits based on fatty acid biomarkers.The results of the eight main catches showed that the value for PUFA/SFA was 0.88~1.79 and that for n-3/n-6 was 2.56~3.18.C16:1 n7,Σ15+Σ17 increased significantly in summer(P<0.05).The EPA+DHA,PUFA/SFA,n-3/n-6,C20:4 n6,C22:6 n3,andΣ22+Σ24 increased and C20:1+C22:1 decreased significantly in autumn(P<0.05).Previous studies have shown that the nutritional value of each catch is high and was significantly higher in autumn than in spring and summer.The nutritional value of Collichthys lucidus and Larimichthys polyactis was the highest.DHA/EPA and cluster analysis divided the catches into three groups:Parapenaeopsis hardwickii,Metapenaeus joyneri and Charybdis japonica;Coilia mystus,Johnius belangerii,C.lucidus and L.polyactis;Pampus argenteus.P.hardwickii,M.joyneri and C.japonica preferred phytoplankton and benthos.L.polyactis and C.mystus preferred zooplankton.P.argenteus preferred phytoplankton and zooplankton.C.lucidus and J.belangerii had no obvious preferences.In general,food source on diatoms and bacteria increased significantly in summer.In autumn,food source significantly increased on benthos,dinoflagellates,and terrestrial plants and it decreased on zooplankton.