Abstract:

In order to evaluate the possible ecological risks of transgenic common carp,the present work primarily studied the effects of ‘allfish’ GH transgenic common carp (〖 Cyprinus carpio  L.) on benthic macroinvertebrate structure and biodiversity in an isolation lake during a twoyear period.The main results showed that species richness,abundance,the standing crops and biodiversity of the benthic macroinvertebrate community decreased at different degree after introducing of transgenic fish.The total species composition of benthic macroinvertebrate decreased from 65 to 36,total density from 4973ind/m2 to 3707 ind/m2.However,the total biomass (wet weight) increased from 77136 g/m2 to 97558 g/m2.Oneway AVONA indicated that taxa richness of Oligochaeta,Trichoptera and Chironomidae,density of Oligochaeta,Trichoptera and Gastropoda,and biomass of Trichoptera showed significantly decreased.Instead of  Parafossarulus striatulus  and  Branchiura sowerbyi,Chaoborus sp.and  Bellamya  sp.became the dominant taxa.Biodiversity indices (Margalef’s,Simpson and ShannonWiener index) and species richness decreased 19%~44% and 38%,respectively and Kdominate curves also showed that biodiversity decreased after introducing of transgenic fish.It might be true that the difference of pressure of predation,prey preference and prey sizeselection between transgenic fish and common carp play important roles in changing benthic macroinvertebrate community and biodiversity.However,further works should be carried out to conform to our preliminary result.