The Analysis Of Microbial Diversity Of Diatoms And Cyanobacteria From The Mudskipper Farm In Two Culture Model

The analysis of molecular diversity of diatoms and cyanobacterial communities was conducted by PCR-DGGE. The materials was respectively took from the sediments of whole sea-water and half sea-water farming of the Lianjiang County of Fujian, China during Jan.2006 to Oct.2006.The species of diatoms and cyanobacterial from the sediments of different farms were analyzed and compared in different period of time respectively. In order to provide scientific proof for artificial controling of diatoms and cyanobacterial in mudskipper(Boleophthalmus pectinirostris) farm. The present study could be useful to clarify mudskipper's main edible diatoms and cyanobacterial in different aquatic cultivation models and seasons.The results showed that the diversity of diatoms and cyanobacterial was much more richer under the half sea-water farming condition, comparing with the whole sea-water farming condition. It revealed that half sea-water farming condition could provide more abundant edible algae. And it was more conducive to mudskipper aquaculture. The change of one year of genetic diversity appears in double-peak curve. Algae composition showed that dominant species were diatoms in two different salinity farms. These species belonged to 27 genera in 2 phyta were identified.Under half the sea-water aquiculture methods,in which 14 taxa in 4 genera belonged to Bacillariophyta,and 1 taxa in 1 genera for cyanobacterial, respectively. Under the entire sea-water aquiculture methods,in which 7 taxa in 4 genera belonged to Bacillariophyta,and 2 taxa in 2 genera for cyanobacterial,respectively.The analysis of algae diversity in mudskipper breeding farms in different seasons found three annual main algae . NCBI BLAST analysis revealed that , three segment shared the highest identity with Thalassiosira weissflogii (AJ319827.1),Haslea salstonica(AF514854.1),Leptolyngbya sp(AF317507.1), and they had close genetic relationships . Diatoms were dominant phylum of algae in the breeding farm ecosystem in 8,9,10 months, followed by cyanobacterial. In Janauary,February,April,June, diatoms and cyanobacterial were both dominant phylum of algae.In August, diatoms were the main species in the sediments of breeding farms, in half sea-water the main algae were Thalassiosira and Hasle.sp, while in whole sea-water Thalassiosira was the dominated species. This gene segment of algae shared the highest identity with Thalassiosira weissflogii who was a member of the diatoms ,and the homology was up to 99%.In September, Thalassiosira,Chaetoceros,Nitzschia and Phaeodactylum were the main algae in breeding farm's. Due to the rainy season, the diversity of diatoms and cyanobacterial reached the lowest value in June. There are only some Thalassiosira,Chaetoceros,Haslea.sp,but still exist 13 kinds of cyanobacteria including Anabaena,meanwhile the proportion with cyanobacterial is higher(48.1%) in all algae.The results of the study preliminarily illustrated the diversity of annual variation rules in the sediments of mudskipper culturing farm that in different cultured environments. The foundation for further study of mudskipper main feeding algae in different conditions and season. Furthermore, this provided an important basic data to realize mudskipper feeding algae of artificial regulation and cultivate. Aim to the separation of algae and the selection of mudskipper artificial feeding algae and artificial mudskipper food and solve the problem of lack of mudskipper algae food and promoting the development of mudskipper culture.