Taxonomic diversity of fish species in Dongshan Bay, China and adjacent areas

Abstract

Within this research,fish species data were collected by four bottom trawl surveys within the coastal waters of Dongshan Bay,China and adjacent areas from November 2009 to August 2010.The inclusion index at the taxonomic level(TINCLi),taxonomic diversity(Δ+ and Λ+) and the index of relative importance(IRI) were calculated.The characteristics of fish community structure and seasonal variation within this sea were in addition analyzed.The results showed that 114 fish species involving 15 orders,57 families and 81 genera were identified in Dongshan Bay and adjacent areas,with Perciformes comprising the major order.Analysis by the inclusion index at the taxonomic level showed that the average numbers of(families,genera,species),(genera,species) and(spe-cies) per order,family and genus were(3.80,5.40,7.60),(1.42,2.00) and(1.41),respectively.Compared to the East China Sea Continent Shelf,Daya Bay and Dongsha Islands,results for Dongshan Bay and adjacent areas were far lower and the species composition more dispersed.The values indicated that taxonomic diversity within Dongshan Bay and adjacent areas was higher than for other seas.PRIMER 5.2 was used to test the average taxo-nomic distinctness(Δ+) and the variation in taxonomic distinctness(Λ+) of Dongshan Bay and adjacent areas.The average taxonomic distinctness(Δ+) was 65.8 and the variation in taxonomic distinctness(Λ+) was 129.5.When comparing the Δ+ with those of the other three seas,the genetic relationship of the composition of fish species in Dongshan Bay and adjacent areas was more distant than that of the other three seas,and had an uneven distribution.The results of the index analyses of relative importance showed that there were three dominant species occurring in autumn and one,two and four in winter,spring and summer,respectively,whose IRI indexes were higher than 1000.The results indicated that the dominant fish species changed according to the different seasons.The compo-sition of fish species at the species level was analyzed in the research,and these data can provide references for sustainable development,utilization and conservation within Dongshan Bay and adjacent areas.