摘要
通过对海南省清澜湾水域采集的悬浮颗粒物、红树叶片、海草、大型海藻以及长鳍篮子鱼（Siganus canaliculatus）和星篮子鱼（Siganus guttatus）的碳、氮稳定同位素比值和脂肪酸组成特征的分析,对该水域篮子鱼的食物来源进行了识别.结果表明：这2种篮子鱼的δ13C值与海藻、悬浮颗粒物的较接近,而与海草、红树叶片的有显著差异;结合这2种篮子鱼体内的硅藻标志脂肪酸（C16∶1n-7）含量较低（＜3％）而大型海藻标志脂肪酸（C18∶2n-6、C18∶3n-3）含量较高的特征,确定篮子鱼的主要食物来源为大型海藻.这2种篮子鱼中,长鳍篮子鱼体内的C22：6n-3含量显著高于星篮子鱼,而C18∶2n-6＋ C18∶3n-3含量则显著低于后者（p＜0.05）,且个体间差异较大,同时长鳍篮子鱼的C18：1 n-7/C18：1n-9含量比值（0.4 ～0.7）低于星篮子鱼（0.8±0.2）,表明长鳍篮子鱼的食物来源中动物性食物的比例明显高于星篮子鱼.这与长鳍篮子鱼的δ15N值高于星篮子鱼,处于更高营养级的结果相一致.这2种篮子鱼虽然不直接摄食δ13C值偏负的红树凋落物,但其食源中可能包含部分以红树凋落物为食的小型动物,从而导致篮子鱼的δ13C值比大型海藻的偏负,其中动物性食物比例较高的长鳍篮子鱼偏负的程度也较高.生物标志物法所反映的篮子鱼食物来源与传统的渔业生态学的认识基本一致,这一方法在食物网营养关系研究中具有较高的应用价值.
Carbon and nitrogen stable isotopes and fatty acid composition of suspended particles,mangrove leaves,seagrass,macroalgae and 2 species Siganus （Siganus canaliculatus and Siganus guttatus）,collected from Qinglan Bay Hainan Province,were analyzed.Diet sources of Siganus canaliculatus and Siganus guttatus were identified with stable carbon and nitrogen isotopes and fatty acid composition.The average δ13C values of 2 species Siganus were similar with those of seston samples collected in Bamen Bay and macro algae and different with those of seagrass and mangrove leaves.The low C16：1n-7 concentration（＜ 3％） and high C18：2n-6,C18：3n-3 concentrations indicated that macroalgae was the diet source of Siganus in Qinglan Bay.The C22：6n-3 concentration in Siganus canaliculatus was significantly higher than that of Siganus guttatus,but C 18：2n-6 ＋ C 18：3 n-3 concentration was lower than Siganus guttatus （p ＜0.05）,and the difference among individuals was big.The C18：1n-7/C18：1n-9concentration ratio of Siganus canaliculatus （0.4 ～ 0.7） was also lower than that of Siganus guttatus （0.8 ± 0.2）.These results indicated that fauna contribute to the diet of Siganus canaliculatus.The δ15N also suggested that trophic level of Siganus canaliculatus was higher than Siganus guttatus.Though Siganus didn＇t prey on the mangrove litter,some micro-fauna may be part of their diet suggested by their depleted 13C than macroalgae,and Siganus canaliculatus was more depleted than Siganus guttatus because the percentage of fauna in their diet was higher.The diet sources of Siganus identified with biomarkers were consistent with traditional fisheries ecology,which means that the biomarkers are applicable in study on trophic relation of food web.
出处
《应用海洋学学报》
CAS
CSCD
2013年第4期540-548,共9页
Journal of Applied Oceanography
基金
国家自然科学基金资助项目(40830850
41021064)
华东师范大学河口海岸学国家重点实验室资助项目(2010RCDW04)
