Difference in the feeding contents of three hermit crabs in the coral reefs of the Nansha Islands,South China Sea
Hermit crab is a type of marine benthic animal.The complex structure of coral reefs makes it one of the areas with the highest diversity of hermit crabs.In response to changes in environmental conditions,such as increasing coverage of benthic algae,small benthic organisms such as hermit crabs can quickly adapt to changes in food resources and play a similar function to herbivorous fishes in maintaining the health of coral reef ecosystems.However,little is known about the differences in food composition on site and ecological functional positioning of different hermit crab species.In this study,three dominant hermit crab species were collected from the coral reef of the Nansha Islands in the spring of 2019:Dardanus lagopodes,Calcinus morgani,and Ciliopagurus strigatus,and their on-site food composition was analyzed using high-throughput sequencing technology.The results showed that there were nine phyla of food types for the three species of hermit crabs,including Rhodophyta,Pyrrophyta,Phaeophyta,Chlorophyta,Arthropoda and Bryozoa,etc.All three hermit crab species fed mainly on algae,including large amounts of Rhodophyta and Pyrrophyta algae(37.75%and 21.14%),and small amounts of Chlorophyta algae(3.13%).But the food composition of different hermit crab species was specific.Calcinus morgani fed mainly on algae turf and detritus and was a herbivorous hermit crab.Ciliopagurus strigatus took Ostracoid from epilithic algal matrix(EAM)as the main food source,accompanied by some branching coralline algae and filamentous Phaeophyta algae.Dardanus lagopodes fed on crustose coralline algae(CCA),macroalgae and epiphytic bryozoans.The results revealed obvious differences in the main foods of marine hermit crabs.Combined with the analysis of ecological niche overlap,it is found that the overlap of the three species of hermit crabs was low(0.059).The feeding areas of Dardanus lagopodes and the other two hermit crab species may not overlap in degraded coral reef areas dominated by CCA.Dardanus lagopodes plays an important role in clearing CCA and bryozoans,and maintaining the healthy development of coral reefs.Ciliopagurus strigatus and Calcinus morgani,as secondary consumers,transfer energy more efficiently to the upper level.These research results extend the previous understanding of the ecological status of hermit crabs.
万方数据
维普
