Feeding ecology of Hexagrammos agrammus in Lidao Rongcheng,China

JI Dongping;BIAN Xiaodong;SONG Na;GAO Tianxiang;Institute of Evolution and Marine Biodiversity,Ocean University of China;Chinese Academy of Fishery Sciences,Yellow Sea Fisheries Research Institute;

Hexagrammos agrammus;;feeding ecology;;stomach contents analysis;;DNA barcoding;;Lidao Rongcheng

The feeding ecology of Hexagrammos agrammus was investigated for 743 individuals collected monthly from the Lidao Rongcheng shore reef(March 2010 and February 2011).The main results of this study are as follows.H.agrammus,a demersal-feeding fish,had 11 prey groups with polychaeta dominating.Prey groups also included fish eggs,algae,seagrass,stomatopoda,amphipoda and other fish.The dietary composition of the prey consumed had obvious seasonal variations.While polychaeta was an important prey group across all seasons,stomatopoda and decapoda were predominant in spring,fish and crabs in summer,fish eggs and fish in autumn,while fish eggs were eaten mostly in winter.The dietary composition also had obvious ontogenetic variations: <80 mm SL(standard length) consumed seagrass and algae,80–199 mm SL consumed polychaeta,fish,decapoda and crabs,while >199 mm SL consumed fish,polychaeta and fish eggs.The feeding intensity had obvious seasonal variations,being highest in summer and lowest in winter.The feeding intensity also had obvious ontogenetic variations,reaching the highest feeding intensity in <100 mm SL,then decreasing with increasing standard length,and gradually increasing after >180 mm SL.Five samples could be identified by DNA barcoding,among which,four were identified at species level and one at genus level.Therefore,the feeding habits of H.agrammus display seasonal and ontogenetic variations,along with variations in species consumption and abundance.